KR100805035B1 - Combustion control method of mixed gas in reheating furnace using calorific value - Google Patents

Abstract

A combustion control method of mixed gas in a reheating furnace is provided to perform optimum combustion of mixed gas by correcting variation of the required theoretical amount of air on the basis of the variation of calorific value caused due to the variation of components of mixed gas. A combustion control method of mixed gas in a reheating furnace, includes a first step(S300) of measuring the temperature in the reheating furnace, and the amount of mixed gas and amount of air supplied to a burner of the reheating furnace, a second step(S302) of calculating a preset value of mixed gas supplied to the burner of the reheating furnace corresponding to the variance between the temperature value of the reheating furnace and a preset temperature value, a third step(S304) of calculating the variance between the preset value of mixed gas and the measured value of mixed gas, and controlling the amount of mixed gas supplied to the burner so as to reduce the variance, a fourth step(S306,S308) of calculating the calorific value of mixed gas in accordance with the composition of mixed gas supplied to the burner, and calculating a theoretical amount of air corresponding to the calculated calorific value by using the relationship between the preset calorific value and the theoretical amount of air, a fifth step(S312) of setting an air-fuel ratio by applying the calculated theoretical amount of air, a sixth step(S314) of calculating a preset value for air amount corresponding to the amount of mixed gas supplied to the burner by using the preset value of mixed gas, detected value of mixed gas and the preset air-fuel ratio, and a seventh step(S316) of calculating the variance between the preset air amount and the measured value of air amount, and controlling the amount of air supplied to the burner so as to reduce the variance.

Description

Combustion Control Method of Mixed Gas Combustion in Heating Furnace Using Calorie Information {COMBUSTION CONTROL METHOD OF MIXED GAS IN REHEATING FURNACE USING CALORIFIC VALUE}

1 is a configuration diagram of a mixed gas combustion control apparatus of a conventional heating furnace.

2 is a configuration diagram of a mixed gas combustion control apparatus of a heating furnace to which the present invention is applied.

3 is a flow chart showing a mixed gas combustion control method of a heating furnace using calorie information according to the present invention.

 Explanation of symbols on the main parts of the drawings

10: heating furnace 30: burner

40: temperature measuring unit 50: mixed gas flow rate control valve

51: mixed gas flow rate detection unit 60: air flow rate control valve

61: air flow detection unit 110: temperature control unit

120: cross limit function unit 130: mixed gas flow control unit

140: multiplication unit 150: air flow control unit

160: air-fuel ratio setting unit 170: calorie analysis unit

180: caloric compensation unit 190: application delay calculation unit

The present invention relates to a combustion control method of a mixed gas, and in particular, in the combustion equipment using the mixed gas to control the combustion of the mixed gas by applying an appropriate theoretical air amount variably in response to the heat amount of the mixed gas which is changed by various factors. The present invention relates to a combustion control method of a mixed gas using calorie information.

In a steelmaking process, such as a heating furnace, a heating equipment such as slabs, billets, and the like is uniformly heated to enable rolling, and is usually made of a preheating zone, a heating zone, and a cracking zone. In such a furnace, the atmospheric temperature is set in consideration of the extraction target temperature according to the heating material and the residence time in the furnace. The ambient temperature is formed by injecting fuel gas used as a heat source and air used for combustion in the furnace to combust it using a burner. The fuel gas typically uses a mixed gas in which COS (Coke Oven Gas) generated in a coke oven and BFG (Blast Furnace Gas) or LDG (Linz Donawitz Converter Gas) generated in a blast furnace are mixed.

In such a furnace, in order to burn the mixed gas, a certain amount of air must be injected in accordance with the amount of the mixed gas injected. In the combustion of the furnace, the amount of air injected for combustion is represented by the excess air ratio, which is represented by the ratio of the actual amount of injected air and the theoretical air amount. Here, the theoretical air amount means the amount of air required to completely burn the mixed gas that can be burned.

In this way, it is important to efficiently burn the fuel by generating an appropriate amount of heat according to the heating material. To this end, it is necessary to appropriately control the amount of mixed gas and air injected according to the heating material.

1 is a block diagram of a mixed gas combustion control apparatus of a conventional heating furnace.

Referring to FIG. 1, the temperature measuring unit 40 measures the temperature inside the heating furnace, and the temperature control unit 110 compares the internal temperature measurement value of the heating furnace with a preset heating internal temperature setting value, and the deviation thereof. And calculate the mixed gas amount set value S1 supplied to the burner 30 of the heating furnace in order to reduce the deviation in response to the deviation. The mixed gas amount set value S1 output from the temperature controller 110 is input to the mixed gas flow controller 130 and the multiplier 140 through the cross limit function 120, respectively. The mixed gas flow rate controller 130 receives the mixed gas flow rate detection value from the mixed gas flow rate detection unit 51 that detects the flow rate of the mixed gas input to the burner 30 of the heating furnace, and the mixed gas flow rate detection value and The mixed gas flow rate control valve 50 is controlled to adjust the flow rate of the mixed gas flowing into the burner 30 by using the mixed gas amount set value in the temperature control unit 110. The multiplier 140 may be configured according to a mixed gas amount set value input from the temperature control unit 110, a mixed gas flow rate detected value detected by the mixed gas flow rate detection unit 130, and an air-fuel ratio setting unit 160. The air amount setting value is calculated according to the mixed gas flow rate detection value and the air-fuel ratio by using a preset air-fuel ratio, and outputs to the air flow controller 150. The air flow rate controller 150 receives an air flow rate detection value from an air flow rate detection unit 61 that detects a flow rate of air input to the burner of the heating furnace, and the air flow rate flow rate detection value and the multiplier 140. The air flow rate control valve 60 is controlled to adjust the flow rate of the air flowing into the burner 30 using the air amount set value output from the burner 30.

This adjusts the amount of mixed gas and air flowing into the burner 30 so that the measured temperature in the furnace is equal to the set temperature of the furnace so that optimum combustion is performed in the furnace.

The cross limit function unit 120 has a function of limiting a set value of the amount of mixed gas so that complete combustion is always performed in a heating furnace. In other words, when the temperature is raised, the mixed gas should be raised, but if the mixed gas is larger than the amount of air, unstable combustion occurs. In this case, the amount of mixed gas should be limited to match the current amount of air, and when the temperature is lowered, the amount of mixed gas should be lowered. In contrast, it has a function of limiting the amount of excessive mixed gas is not reduced.

Here, the most important thing in the combustion in the furnace is that the optimum combustion is achieved only when the mixed gas and the air volume are burned at a constant ratio. For this purpose, it is important to supply the theoretical air amount according to the flow rate of the mixed gas. However, in the related art, the theoretical air amount is always set based on a constant mixed gas, and thus the air-fuel ratio is set according to the fixed theoretical air amount. COG and BFG used as a mixed gas are constantly changed according to the operating environment of the coke and blast furnace plant, and the amount of heat supplied to the furnace is changed from time to time due to the change in calorie control. The fixed amount of theoretical air is applied, which does not correspond to the change in the composition of the mixed gas, thereby causing incomplete combustion or excessive air combustion in the combustion by the amount of change in the theoretical air amount necessary for the complete combustion of the mixed gas (eg, Korean Patent Application Publication). Publication 2003-55372).

The present invention has been proposed to solve the above-described problems, and by supplying by correcting the change in the theoretical air amount required based on the change in the calorie information generated according to the change in the composition of the mixed gas composition in the furnace It is an object of the present invention to provide a mixed gas combustion control method of a heating furnace using calorie information that enables optimum mixed gas combustion to be performed.

Mixed gas combustion control method of the heating furnace using the calorie information according to the present invention for achieving the above object,

A first step of measuring the temperature inside the furnace, and the amount of mixed gas and air supplied to the burner of the furnace, respectively; A second step of calculating a set value of the amount of mixed gas supplied to a burner of the heating furnace corresponding to a deviation value between the temperature measured value of the heating furnace and a preset temperature setting value; A third step of calculating a deviation between the mixed gas amount set value and the mixed gas amount measured value and adjusting the amount of mixed gas supplied to the burner to reduce the deviation; A fourth step of calculating a calorific value of the mixed gas according to the composition of the mixed gas supplied to the burner, and calculating a theoretical air amount corresponding to the calculated calorific value using a correlation between a preset calorific value and a theoretical air amount; A fifth step of setting an air-fuel ratio by applying the calculated theoretical air amount; A sixth step of calculating an air amount setting value corresponding to the amount of the mixed gas supplied to the burner by using the mixed gas amount setting value, the mixed gas amount detection value, and the set air-fuel ratio; And a seventh step of calculating a deviation between the air quantity setting value and the air quantity measurement value and controlling the amount of air supplied to the burner to reduce the deviation.

In an embodiment of the present disclosure, the fifth step may include determining whether a predetermined delay time D has elapsed; And applying the calculated theoretical air amount to the air-fuel ratio setting when the delay time D has elapsed.

In this case, the delay time (D) is preferably calculated through the following equation.

Here, DelayTime is the delay time (D) (sec), Q is the flow rate of the mixed gas supplied to the furnace burner (㎥ / sec), A is the cross-sectional area (㎡) of the pipe to which the mixed gas is moved, v is the mixing The gas velocity (m / sec), L, is the distance (m) between two points at which the mixed gas is moved.

In the following, a detailed description of a preferred embodiment of the present invention will be described with reference to the accompanying drawings. In the following description of the present invention, in the case where it is determined that detailed descriptions of related well-known functions or configurations may unnecessarily obscure the subject matter of the present invention, detailed descriptions thereof will be omitted so as not to obscure the subject matter of the present invention. will be.

2 is a configuration diagram of a mixed gas combustion control apparatus of a heating furnace to which the present invention is applied.

Referring to FIG. 2, the temperature in the heating furnace is measured by the temperature measuring unit 40 and transmitted to the temperature control unit 110. The temperature control unit 110 compares the temperature set value inside the furnace set by the temperature setting unit (not shown) with the temperature measured value inside the furnace measured by the temperature measuring unit 40, and calculates a deviation thereof. In response to the deviation, the mixed gas amount setting value S1 for controlling the amount of the mixed gas supplied to the burner 30 of the heating furnace is reduced and output so as to reduce the deviation.

The mixed gas amount and the air amount set value S1 output from the temperature control unit 110 are input to the cross limit function unit 120. The cross limit function unit 120 has a function of limiting a set value of the amount of mixed gas so that complete combustion is achieved in a heating furnace. In other words, when the temperature is raised, the mixed gas must be raised, but when the amount of mixed gas is greater than the amount of air, unstable combustion occurs. In this case, the amount of mixed gas must be limited to match the current amount of air, and when the temperature is lowered, the amount of mixed gas must be lowered. To limit the amount of excessive gas mixture is reduced. The control signal output from the cross limit function unit 120 is input to the mixed gas flow rate controller 130 and the multiplier 140.

The mixed gas flow rate detection unit 51 detects the flow rate of the mixed gas supplied to the burner 30 of the heating furnace, and transmits the mixed gas flow rate detection value to the mixed gas flow rate control unit 130. The mixed gas flow rate controller 130 uses the mixed gas flow rate detection value input from the mixed gas flow rate detector 51 and the mixed gas amount set value S1 output from the temperature control part 110 to burner 30. The mixed gas flow rate control valve 50 is controlled to adjust the flow rate of the mixed gas introduced into (S2).

The multiplier 140 may be configured according to the mixed gas amount set value output from the temperature control unit 110, the mixed gas flow rate detected value detected by the mixed gas flow rate detection unit 51, and the air-fuel ratio setting unit 160. Using the set air-fuel ratio, the air amount setting value S3 corresponding to the amount of the mixed gas supplied to the burner 30 is calculated and output to the air flow controller 150. That is, the air amount set value S3 is set to the mixed gas amount set value output from the temperature control unit 110, the mixed gas flow rate detection value detected by the mixed gas flow rate detection unit 51, and the air-fuel ratio set by the air-fuel ratio setting unit 160. Therefore, it becomes a control value which sets the quantity of air supplied to the burner 30 of the said heating furnace. Accordingly, the air flow rate controller 150 controls the amount of air currently supplied according to the set air amount set value S3. More specifically, the air flow rate controller 150 receives an air flow rate detection value from an air flow rate detection unit 61 that detects a flow rate of air input to the burner 30 of the heating furnace, and detects the air flow rate flow rate. Adjust the flow rate of the air flowing into the burner 30 so that the air flow rate detection value matches the air flow rate setting value S3 by using a value and the air flow rate setting value S3 output from the multiplier 140. In order to control the air flow rate control valve 60 (S4).

As a result, the amount of mixed gas and the amount of air flowing into the burner 30 can be adjusted such that the measured temperature in the furnace is equal to the set temperature of the furnace so that the optimum combustion is performed in the furnace.

Here, in the present invention, the theoretical air amount is changed instantaneously according to the composition of the mixed gas. The composition of the mixed gas is usually present as carbon, hydrogen, nitrogen, oxygen, carbon dioxide and a combination of carbon and hydrogen. In these compositions, compositions other than carbon dioxide and nitrogen, which is an inert gas, require an amount of oxygen to make water and carbon dioxide. To this end, the calorie analysis unit 170 analyzes the calories in real time according to the composition of the mixed gas used in the heating furnace. The calorie information according to the composition of the mixed gas analyzed by the calorie analyzer 180 is input to the caloric compensator 180. The calorie compensator 180 calculates the theoretical air amount corresponding to the analyzed calorie information using the calorie information input from the calorie analysis unit 170 by using a correlation between a preset calorie value and the theoretical air amount. The theoretical air calculated in this way means the amount of air required for complete combustion of the mixed gas according to the composition of the mixed gas supplied to the heating furnace. In fact, it is practically impossible to mix the mixed gas in a standard composition and supply it to the heating furnace in a practical manner, and in actual operation, the composition of the mixed gas changes instantaneously. Therefore, complete combustion of the mixed gas can be achieved only when the theoretical air amount changes instantaneously corresponding to the composition of the mixed gas. In the present invention, the theoretical air amount is instantaneously calculated using calorie information according to the composition of the mixed gas. As described above, the theoretical air amount is calculated so as to correspond to the composition of the mixed gas which is changed instantaneously, and the combustion efficiency can be improved due to the complete combustion of the mixed gas by applying the calculated theoretical air amount to the combustion of the heating furnace.

As described above, the theoretical air amount calculated by the calorific value compensator 180 is input to the application delay time calculator 190. The application delay time calculation unit 190 applies the calculated theoretical air amount to the air-fuel ratio setting in the mixed gas combustion of the heating furnace. In more detail, in applying the theoretical air amount calculated as above to the mixed gas combustion in the heating furnace, a certain time delay may occur. For example, the measurement of the composition of the mixed gas or the calorific value of the mixed gas may necessarily involve a time delay (D1), and furthermore, the time delay (D2) according to the moving distance until the mixed gas reaches the final combustion point along the pipe. This may occur. Of the two delay times (D1, D2) generated as described above, the delay time (D1) according to the measurement of the composition of the mixed gas or calories of the mixed gas is a constant constant, but the time delay (D2) according to the moving distance of the mixed gas. Is a variable according to the flow rate and the distance of the mixed gas to be moved. Therefore, when the flow rate and distance of the mixed gas to be moved can be detected, the delay time D2 according to reaching the combustion point of the mixed gas can be calculated. Here, when the delay time (D2) according to the composition measurement of the mixed gas or the calorific value of the mixed gas is subtracted from the delay time (D2) calculated as described above (D2-D1), the calorific compensation unit 180 calculates The final delay time D can be calculated to correct the theoretical air volume. The application delay time calculating unit 190 calculates a final delay time for correcting the theoretical air amount calculated by the caloric compensation unit 180 as described above, and delays the calculated theoretical air amount for the final delay time. The air-fuel ratio setting unit 160 is transmitted. As a result, the air-fuel ratio setting unit 160 sets the air-fuel ratio by varying the air-fuel ratio according to the theoretical air amount, and applies the final delay time to correct the theoretical air amount.

As described above, the present invention calculates the theoretical air amount corresponding to the calorie information of the mixed gas in the heating furnace, and sets the air-fuel ratio by varying the theoretical air amount required according to the change of the mixed gas composition. At this time, by setting the air-fuel ratio by reflecting the delay time that can correct the theoretical air amount according to the change of the mixed gas composition, it is possible to implement the complete combustion when controlling the mixed gas combustion in the furnace.

3 is a flow chart showing a mixed gas combustion control method of a heating furnace using calorie information according to the present invention.

Referring to FIG. 3, a deviation value is calculated by comparing the measured temperature inside the heating furnace detected by the temperature detector 40 with a preset temperature inside the preset heating furnace (S300). In response to the deviation value, the set amount of mixed gas amount S1 for controlling the amount of mixed gas supplied to the burner 30 of the heating furnace is reduced (S302) so as to reduce the deviation value (S302). Subsequently, a deviation between the mixed gas amount measured value measured by the mixed gas flow rate detection unit 51 and the mixed gas amount set value calculated by the temperature control unit 110 is calculated and supplied to the furnace burner 30 to reduce the deviation. The flow rate of the mixed gas is controlled (S304). More specifically, the step S304 controls the mixed gas flow rate control valve 50 to adjust the flow rate of the mixed gas flowing into the burner 30 in response to the deviation value in the mixed gas flow rate controller 130.

Next, the amount of heat is calculated according to the composition of the mixed gas supplied to the burner 30 of the heating furnace (S306). The theoretical air amount corresponding to the heat amount of the mixed gas is calculated using the correlation between the heat amount and the theoretical air amount from the calculated heat amount (S308). Preferably, the correlation between the calorie value and the theoretical air amount is predefined. In applying the calculated theoretical air amount to the air-fuel ratio setting as described above, wait until a predetermined delay time D elapses (S310), and if the delay time D elapses, the calculated air-fuel ratio is applied by applying the calculated theoretical air amount. Set (S312). This air-fuel ratio setting is for varying the theoretical air amount as the composition of the mixed gas changes instantaneously. That is, calorie information is calculated using the composition of the mixed gas, and the theoretical air amount corresponding to the calorie information is calculated to correct the theoretical air amount according to the change of the mixed gas composition.

Subsequently, the mixed gas amount set value calculated by the temperature control unit 110, the mixed gas amount detected value detected by the mixed gas flow rate detection unit 51, and the air-fuel ratio set by the air-fuel ratio setting unit 160 are used to determine the current mixed gas amount. The corresponding air amount set value S3 is calculated (S314). Calculate the deviation between the air amount set value S3 calculated as described above and the air amount measured value measured by the air flow rate detection unit 61, and the flow rate of the air supplied to the furnace burner 30 so as to reduce the deviation. Control (S316). That is, the step S316 is an air flow rate control valve 50 to adjust the flow rate of the air flowing into the burner 30 in response to the deviation between the calculated air amount set value and the air amount measurement value in the air flow control unit 150 ) To control.

Thus, in controlling the amount of mixing and the amount of air supplied to the burner 30 of the heating furnace, the theoretical air amount is calculated according to the calorie information of the mixed gas, and this is applied to the air-fuel ratio setting. At this time, the amount of heat changes according to the composition of the mixed gas in actual operation.In response to this change, the theoretical air amount is variably corrected and applied to the air-fuel ratio, so that the combustion efficiency can be improved even when the mixed gas changes. do.

An embodiment of the present invention will be described below.

In an embodiment in which the mixed gas according to the present invention includes COG and BFG, the combustion reaction of the mixed gas is shown in Chemical Formula 1 below.

H ₂ + 1/202 = H ₂ O (1-1)

CH ₄ + 202 = C0 ₂ + 2H ₂ O (1-2)

CO + 1/202 = CO ₂ (1-3)

CH ₂ H ₄ + 302 = 2CO ₂ + 2H ₂ O (1-4)

The gas composition ratio in the COG is set as shown in Table 1 below.

Mixed gas composition CO ₂ O ₂ CO H ₂ CH ₄ N ₂ C ₂ H ₄ COG (Vol%) 3.1 0.3 8.4 56.4 26.6 2.3 2.9 BFG (Vol%) 20.7 - 22 3.2 - 54.1 -

In this case, by calculating the theoretical air amount of the mixed gas having a COG ratio of 100%, it is possible to know the amount of oxygen required for each composition in each combustion reaction equation. That is, in Formula (1-1) of Formula 1, H ₂ occupies 56.4% (0.564) in COG, and since the required oxygen amount is 1/2, it becomes 0.5. When the required oxygen amount is obtained in this manner, the following equation (1) is obtained.

(0.564 x 0.5) + (0.266 x 2) + (0.084 x 0.5) + (0.029 x 3) = 0.943 (1-5)

Here, since the amount of oxygen in Table 1 itself is 0.003, the amount excluding this is 0.94. When this is converted into the amount of oxygen in the air, the amount of oxygen in the air occupies 21%, so the final theoretical air amount is 4.476 (= 0.94 / 0.21).

Next, when the calorific value of the mixed gas having a COG ratio of 100% is calculated based on Equation 1 and Table 1 according to an embodiment of the present invention, the unit calorie value is determined for each composition in Formula 1. That is, H ₂ is 2570 Kcal / Nm ³ , CH ₄ is 8550 Kcal / Nm ³ CO is 3020 Kcal / Nm ³ , and C ₂ H ₄ is 14320 Kcal / Nm ³ .

When the total calorific value of the mixed gas is calculated using the unit calorific value of each composition, it is expressed as Equation 2 below.

(0.564 x 2570) + (0.266 x 8550) + (0.084 x 3020) + (0.029 x 14320)

= 4392.74 (Kcal / Nm ³ ) (1-6)

Here, when the COG ratio is 100%, the theoretical air amount and calorific value can be obtained based on Chemical Formula 1 and Table 1. That is, if only the ancestor of the mixed gas can be known, the theoretical air amount and calorific value can be calculated as described above. The mixed gas composition, calorific value and theoretical air amount according to one embodiment of the present invention thus obtained are shown in Table 2 below.

Mixed gas composition COG Ratio Item COG BFG 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% CO ₂ 3.1 20.7 20.7 18.9 17.2 15.4 13.7 11.9 10.1 8.4 6.6 4.9 3.1 O ₂ 0.3 0 0 0 0 0.1 0.1 0.2 0.2 0.2 0.2 0.3 0.3 CO 8.4 22 22 20.6 19.3 17.9 16.6 15.2 13.8 12.5 11.1 9.8 8.4 H ₂ 56.4 3.2 3.2 8.5 13.8 19.2 24.5 29.8 35.1 40.4 45.8 51.1 56.4 CH ₄ 26.6 0 0 2.7 5.3 8 10.6 13.3 16 18.6 21.3 23.9 26.6 N ₂ 2.3 54.1 54.1 48.9 43.7 38.6 33.4 28.2 23 17.8 1.7 7.5 2.3 C ₂ H ₂ 0 0 0 0 0 0 0 0 0 0 0 0 0 C ₂ H ₄ 2.9 0 0 0.3 0.6 0.9 1.2 1.5 1.7 2 2.3 2.6 2.9 C ₂ H ₆ 0 0 0 0 0 0 0 0 0 0 0 0 0 calorie 747 1112 1477 1841 2206 2571 2936 3301 3365 4080 4395 Theoretical air volume 0.6 0.99 1.38 1.77 2.16 2.55 2.94 3.32 3.71 4.1 4.49

Intervals (eg, values between 10% and 20%) of the COG ratios shown in Table 2 may be determined using interpolation.

On the other hand, as described above, the theoretical air amount calculated by the calorific compensation unit 180 is input to the application delay time calculation unit 190, the application delay time calculation unit 190 converts the calculated theoretical air amount of the heating furnace Applies to setting the air-fuel ratio for mixed gas combustion. At this time, a certain time delay may occur in applying the theoretical air amount calculated as described above to the combustion of the mixed gas in the furnace, so that a more efficient combustion of the mixed gas in the furnace can be realized by compensating for the delay time. do.

As described above, the delay time for applying the theoretical air amount is largely two. One is the measurement delay time and the other is the mixed gas moving speed delay between the application position and the measurement position. The former can be obtained through manual and actual measurements of the measuring device. The moving speed delay can be easily obtained through Equation 3 below.

(1-7)

(1-7)

(1-8)

(1-8)

Here, DelayTime is the delay time (D) (sec), Q is the flow rate of the mixed gas supplied to the burner (㎥ / sec), A is the cross-sectional area (㎡) of the pipe to which the mixed gas is moved, v is the The moving speed (m / sec), L is the distance (m) between two points at which the mixed gas is moved.

By setting the air-fuel ratio by applying the calculated theoretical air amount to the air-fuel ratio as described above, it is possible to realize efficient combustion of the mixed gas by controlling the air-fuel ratio according to the change in calorific value of the mixed gas.

The drawings and detailed description of the invention are merely exemplary of the invention, which are used for the purpose of illustrating the invention only and are not intended to limit the scope of the invention as defined in the appended claims or claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible from this. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the present invention, it is possible to prevent incomplete combustion or excess air combustion by varying and applying an appropriate theoretical air amount in response to the heat amount of the mixed gas fluctuated by various disturbances, resulting in energy saving as well as scale generation due to improved thermal efficiency. It can contribute to improving the quality of the steel sheet product through reduction.

Claims (3)

A first step of measuring the temperature inside the furnace, and the amount of mixed gas and air supplied to the burner of the furnace, respectively; A second step of calculating a set value of the amount of mixed gas supplied to a burner of the heating furnace corresponding to a deviation value between the temperature measured value of the heating furnace and a preset temperature setting value; A third step of calculating a deviation between the mixed gas amount set value and the mixed gas amount measured value and adjusting the amount of mixed gas supplied to the burner to reduce the deviation; A fourth step of calculating a calorific value of the mixed gas according to a composition of the mixed gas supplied to the burner, and calculating a theoretical air amount corresponding to the calculated calorific value using a correlation between a preset calorific value and a theoretical air amount; A fifth step of setting an air-fuel ratio by applying the calculated theoretical air amount; A sixth step of calculating an air amount setting value corresponding to the amount of the mixed gas supplied to the burner by using the mixed gas amount setting value, the mixed gas amount detection value, and the set air-fuel ratio; And A seventh step of calculating a deviation between the air quantity setting value and the air quantity measurement value and controlling the amount of air supplied to the burner to reduce the deviation; Mixed gas combustion control method of the heating furnace using calorie information comprising a. The method of claim 1, wherein the fifth step, Determining whether a preset delay time D has elapsed; And Applying the calculated theoretical air amount to the air-fuel ratio setting when the delay time D has elapsed; Mixed gas combustion control method of the heating furnace using the calorie information, characterized in that it further comprises. The method of claim 2, The delay time (D) is a mixed gas combustion control method of a heating furnace using calorie information, characterized in that calculated through the following equation.

(DelayTime is the delay time (D) (sec), Q is the flow rate of the mixed gas supplied to the furnace burner (m 3 / sec), A is the cross-sectional area of the pipe in which the mixed gas is moved (m 2), v is the mixed gas) Movement speed (m / sec), L is the distance (m) between two points where the mixed gas is moved)

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