Method and device for controlling the dome temperature of a blast furnace hot blast stove

Abstract

The application discloses a kind of blast furnace hot blast stove vault temperature control method and device, the method includes: using accurate timing function to collect the vault temperature data of multiple periods, collect the residual oxygen content of waste gas of hot blast stove, compare target period vault temperature variation trend and waste residual oxygen content with preset standard, adjust the air-fuel ratio of hot blast stove according to comparison result;Add weight to the calculation factor of air-fuel ratio, adjust air-fuel ratio according to air-fuel ratio calculation factor weight, collect vault temperature after adjusting air-fuel ratio, calculate the temperature variation trend of current sampling time, compare the temperature variation trend of current sampling time with vault temperature standard, modify the weight of air-fuel ratio calculation factor according to comparison result, until the vault temperature after adjusting air-fuel ratio according to the weight of modified air-fuel ratio calculation factor meets vault temperature standard, the application makes hot blast stove furnace burning state reach optimum, effectively guarantee blast furnace production and operation.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, and in particular to a method and apparatus for controlling the temperature of the blast furnace hot blast stove dome. Background Technology

[0002] This section is intended to provide background or context for embodiments of the present invention. The description herein is not intended to imply that it is prior art simply because it is included in this section.

[0003] The burner is located at the dome of the hot blast stove. Most blast furnaces require a hot blast temperature of around 1200℃, necessitating a high dome temperature during combustion to ensure the furnace temperature reaches the required level upon completion. Before 2016, hot blast stoves were required to maintain as high a dome temperature as possible during production to ensure heat storage, as long as it did not exceed the load-bearing capacity of the dome's heat storage bricks. The upper limit for the dome temperature was generally set at 1350℃ to 1400℃.

[0004] Nitrogen oxides are a general term for NO, NO2, N2O, N2O3, etc. If the combustion temperature of the dome flame is too high, the nitrogen oxide content in the exhaust gas will also increase. After 1400℃, the nitrogen oxide content in the exhaust gas will increase sharply. When nitrogen oxides are released into the air, they will react with hydrocarbons in the air to produce photochemical smog and ozone, which do not meet environmental protection requirements.

[0005] Furthermore, if excessively high combustion temperatures are pursued, the combustible gases in the blast furnace gas need to be burned as completely as possible. Pursuing an overly theoretical air-fuel ratio (the ratio of blast furnace gas flow rate to combustion air flow rate) and minimizing the excess air coefficient may result in incomplete combustion of the blast furnace gas, which will increase the carbon monoxide in the exhaust gas. Since the pulverized coal injection process requires exhaust gas from the hot blast stove, the carbon monoxide in the exhaust gas from the hot blast stove will pose a safety risk to the operators in the pulverized coal injection process.

[0006] From the perspectives of environmental protection and safe production, all blast furnaces have imposed height restrictions on the dome temperature. This presents a contradiction: to ensure the blast temperature, the dome temperature needs to be as high as possible, but for environmental protection and safety, the dome temperature cannot be too high. Therefore, each blast furnace site hopes to precisely control the dome temperature, which requires more precise air-fuel ratio control. This is something that manual firing cannot achieve, and traditional automatic firing models often cannot achieve precise dome temperature control either. Summary of the Invention

[0007] This invention provides a method for controlling the temperature of the blast furnace hot blast stove dome, used to precisely control the dome temperature and ensure efficient production of the hot blast stove. The method includes:

[0008] The arch temperature data for multiple cycles is collected using a precise timing function;

[0009] Based on the crown temperature data of each period, fit the crown temperature fitting curve of each period, find the extreme value solution of the crown temperature fitting curve of each period, and obtain the trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve of the target period.

[0010] Based on the trend of the crown temperature fitting curve and the slope of the crown temperature fitting curve for the target period, the crown temperature change trend for the target period is calculated, and the crown temperature change trend for the target period is compared with the preset crown temperature standard.

[0011] Collect the residual oxygen content of the exhaust gas at the current sampling time of the hot blast stove, compare the residual oxygen content of the exhaust gas at the current sampling time with the preset residual oxygen content standard, and adjust the air-fuel ratio of the hot blast stove according to the comparison results of the dome temperature and the residual oxygen content.

[0012] Repeat the following steps until the dome temperature after adjusting the air-fuel ratio according to the weight of the modified air-fuel ratio calculation factor meets the dome temperature standard: Adjust the air-fuel ratio according to the weight of the air-fuel ratio calculation factor, collect the dome temperature and residual oxygen after adjusting the air-fuel ratio, calculate the temperature change trend of the target period, compare the temperature change trend of the target period with the dome temperature standard, compare the residual oxygen with the exhaust gas residual oxygen standard, and modify the weight of the air-fuel ratio calculation factor according to the comparison results.

[0013] This invention also provides a blast furnace hot blast stove dome temperature control device for precisely controlling the dome temperature and ensuring efficient production of the hot blast stove. The device includes:

[0014] The temperature calculation module is used to collect vault temperature data over multiple cycles using a precise timing function;

[0015] The curve calculation module is used to fit the crown temperature fitting curve for each period based on the crown temperature data for each period, and to find the extreme value solution for the crown temperature fitting curve for each period to obtain the trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve for the target period.

[0016] The trend calculation module is used to calculate the crown temperature change trend of the target period based on the crown temperature fitting curve trend and the temperature change slope of the crown temperature fitting curve, and compare the crown temperature change trend of the target period with the preset crown temperature standard.

[0017] The comparison module is used to collect the residual oxygen content of the exhaust gas at the current sampling time of the hot blast stove, compare the residual oxygen content of the exhaust gas at the current sampling time with the preset residual oxygen content standard, and adjust the air-fuel ratio of the hot blast stove according to the comparison results of the dome temperature and the residual oxygen content.

[0018] The adjustment module is used to repeatedly execute the following steps until the dome temperature after adjusting the air-fuel ratio according to the weight of the modified air-fuel ratio calculation factor meets the dome temperature standard: adjust the air-fuel ratio according to the weight of the air-fuel ratio calculation factor, collect the dome temperature and residual oxygen after adjusting the air-fuel ratio, calculate the temperature change trend of the target period, compare the temperature change trend of the target period with the dome temperature standard, compare the residual oxygen with the exhaust gas residual oxygen standard, and modify the weight of the air-fuel ratio calculation factor according to the comparison results.

[0019] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described method for controlling the temperature of the blast furnace hot blast stove dome.

[0020] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for controlling the temperature of the blast furnace hot blast stove dome.

[0021] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-described method for controlling the temperature of the blast furnace hot blast stove dome.

[0022] In this embodiment of the invention, a precise timing function is used to collect arch temperature data for multiple cycles; arch temperature fitting curves for each cycle are fitted based on the arch temperature data for each cycle, and extreme value solutions are obtained for the arch temperature fitting curves for each cycle to obtain the trend and slope of the arch temperature fitting curve for the target cycle; based on the trend and slope of the arch temperature fitting curve for the target cycle, the arch temperature change trend for the target cycle is calculated, and the arch temperature change trend for the target cycle is compared with a preset arch temperature standard; the residual oxygen content of the exhaust gas at the current sampling time of the hot air furnace is collected, and the current sampling... The residual oxygen content in the exhaust gas at any given time is compared with the preset standard. Based on the comparison results of the dome temperature and residual oxygen content, the air-fuel ratio of the hot blast stove is adjusted. The following steps are repeated until the dome temperature after adjusting the air-fuel ratio according to the weight of the modified air-fuel ratio calculation factor meets the dome temperature standard: Adjust the air-fuel ratio according to the weight of the air-fuel ratio calculation factor, collect the dome temperature and residual oxygen content after the adjustment, calculate the temperature change trend for the target period, compare the temperature change trend for the target period with the dome temperature standard, compare the residual oxygen content with the standard residual oxygen content in the exhaust gas, and modify the weight of the air-fuel ratio calculation factor based on the comparison results. In this way, by judging the past trend of the dome temperature and analyzing the feedback effect in real time, the direction of air-fuel ratio adjustment is determined, and the air-fuel ratio is precisely controlled to achieve the goal of precisely controlling the dome temperature. This ensures that the hot blast stove's combustion state reaches its optimal level, effectively guaranteeing blast furnace production and operation. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0024] Figure 1 This is a flowchart of the blast furnace hot blast stove dome temperature control method provided in the embodiments of the present invention;

[0025] Figure 2 This is an example diagram of the arch temperature fitting curve provided in an embodiment of the present invention;

[0026] Figure 3 This is an example diagram of the fitted curve of the arch temperature trend provided in an embodiment of the present invention;

[0027] Figure 4 This is an example diagram illustrating the residual oxygen range provided in an embodiment of the present invention;

[0028] Figure 5 This is an example diagram illustrating the trend of the arch temperature change at the previous sampling time, provided in an embodiment of the present invention.

[0029] Figure 6 This is another example diagram of the residual oxygen range provided in the embodiments of the present invention;

[0030] Figure 7 This is an example diagram illustrating the trend of dome temperature change after adjusting the air-fuel ratio, provided in an embodiment of the present invention.

[0031] Figure 8 This is a schematic diagram of the blast furnace hot blast stove dome temperature control device provided in an embodiment of the present invention;

[0032] Figure 9 This is a structural block diagram of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0034] In this document, the term "and / or" merely describes a relationship, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0035] In the description of this specification, the terms "comprising," "including," "having," and "containing" are open-ended terms, meaning that they include but are not limited to. The terms "an embodiment," "a specific embodiment," "some embodiments," and "for example," etc., refer to specific features, structures, or characteristics described in connection with that embodiment or example that are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. The order of steps involved in the various embodiments is used to illustrate the implementation of this application, and the order of steps is not limited and can be adjusted appropriately as needed.

[0036] This invention provides a method for controlling the temperature of the blast furnace hot blast stove dome, such as... Figure 1 As shown, it includes:

[0037] Step 101: Collect crown temperature data for multiple cycles using a precise timing function;

[0038] Step 102: Fit the crown temperature fitting curve for each period based on the crown temperature data for each period, and find the extreme value solution for the crown temperature fitting curve for each period to obtain the trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve for the target period.

[0039] Step 103: Based on the trend of the crown temperature fitting curve and the slope of the crown temperature fitting curve, calculate the crown temperature change trend of the target period, and compare the crown temperature change trend of the target period with the preset crown temperature standard.

[0040] Step 104: Collect the residual oxygen content of the exhaust gas at the current sampling time of the hot blast stove, compare the residual oxygen content of the exhaust gas at the current sampling time with the preset residual oxygen content standard, and adjust the air-fuel ratio of the hot blast stove according to the comparison results of the dome temperature and the residual oxygen content.

[0041] Step 105: Repeat the following steps until the dome temperature after adjusting the air-fuel ratio according to the weight of the modified air-fuel ratio calculation factor meets the dome temperature standard: Adjust the air-fuel ratio according to the weight of the air-fuel ratio calculation factor, collect the dome temperature and residual oxygen after adjusting the air-fuel ratio, calculate the temperature change trend of the target period, compare the temperature change trend of the target period with the dome temperature standard, compare the residual oxygen with the exhaust gas residual oxygen standard, and modify the weight of the air-fuel ratio calculation factor according to the comparison results.

[0042] The dome temperature is one of the key indicators for hot blast stove operation. Its precise control directly affects the blast furnace's air supply efficiency and significantly impacts the smooth operation of the blast furnace. Because the hot blast stove's conditions and the calorific value of the gas are constantly changing, controlling the dome temperature is very difficult. Excessively high dome temperatures can affect the safety of the regenerator bricks, cause a sharp increase in nitrogen oxide content, and also compromise the safety of the pulverized coal injection process. Conversely, excessively low dome temperatures directly affect the firing efficiency and significantly impact the air supply temperature. The method provided in this invention determines the direction of air-fuel ratio adjustment by judging the dome temperature trend at the previous sampling time and analyzing the feedback effect in real time, thus precisely controlling the air-fuel ratio and achieving precise dome temperature control. This optimizes the hot blast stove's firing state and effectively ensures the smooth operation of the blast furnace.

[0043] In practice, ensure that the gas shut-off valve, air shut-off valve, exhaust gas shut-off valve, nitrogen purging valve, and pressurization valve are all in the correct positions.

[0044] The combustible gases in the furnace gas are mainly CO (carbon monoxide), H2 (hydrogen), and CH4 (methane), which react with O2 (oxygen) in the combustion air to produce CO2 (carbon dioxide) and H2O (water).

[0045] Since methane accounts for a very small percentage of blast furnace gas, it is generally not considered.

[0046] Main molecular reaction formula:

[0047]

[0048]

[0049] In blast furnace gas, the CO content is generally around 21%, and the H2 content is generally around 2%. Based on the reaction formula, it is known that the oxygen content of combustible gas in the combustion air is approximately 20.5%, so an air-fuel ratio of approximately 0.55 is sufficient. However, in actual production, more air than theoretically required must be supplied for complete combustion of the fuel. This excess air is called excess air, and its ratio is called the excess air coefficient, calculated using the following formula:

[0050] Vair = Vgas × R0 × a0

[0051] Where Vgas is the blast furnace gas flow rate; Vair is the combustion air flow rate; R0 is the air-fuel ratio; and a0 is the excess air coefficient.

[0052] From the perspective of dome temperature control, the combustion process of a single hot blast stove can be divided into three stages.

[0053] (a) Combustion start stage, in which the air-fuel ratio depends on the average calorific value of the gas in the previous combustion cycle and air supply cycle.

[0054] The calculation formula is:

[0055] Vair=(Vgas*CO%+Vgas*H2%)÷2÷20.5%×a0

[0056] R0 = Vair ÷ Vgas × a0

[0057] Where Vgas is the blast furnace gas flow rate; Vair is the combustion air flow rate; R0 is the air-fuel ratio; and a0 is the excess air coefficient.

[0058] (b) Full combustion stage: During this stage, the gas flow is sufficient, the hot blast stove dome is filled with combustible gas, and the dome control logic is normal and effective.

[0059] (c) During the enthalpy maintenance stage and the final stage of combustion, the hot blast stove has sufficient heat storage and the gas flow rate is reduced. In order to maintain the dome temperature, the excess air coefficient can be appropriately reduced.

[0060] In one embodiment, fitting a crown temperature fitting curve based on periodic crown temperature data, and finding the extreme value solution of the crown temperature fitting curve, includes:

[0061] The crown temperature data for each period are fitted to obtain the crown temperature data fitting curve;

[0062] Find the extreme values ​​of the fitted curve of the arch temperature data to obtain the eigenvalues ​​of the extreme value arithmetic solution;

[0063] The trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve are determined based on the characteristic values.

[0064] In one specific embodiment, the sampling time is 250 ms, with four samples taken per second. The arithmetic average of the sampled dome temperature, gas flow rate, and air flow rate is calculated. Due to the large lag and slow time-varying characteristics of the hot blast stove control coefficient, a decision is made every minute after the initial combustion period, i.e., the air-fuel ratio is adjusted once. The arithmetic average of the four dome temperatures sampled per second yields 60 dome temperature scatter points per minute. After the initial combustion period, these 60 dome temperature averages are fitted three times every 60 seconds, resulting in the dome temperature fitting curve shown below. Figure 2 。

[0065] Finding the extreme value of the fitted curve of the dome temperature, the arithmetic solution of the extreme value can be obtained (assuming the X-axis coordinate corresponding to the minimum value is x1 and the X-axis coordinate corresponding to the maximum value is x2), and three situations can be obtained:

[0066] a) There is no extreme point (the extreme point is outside the X-axis coordinate axis):

[0067] The fitted curve rises unidirectionally (the maximum value is on the right side of the X-axis coordinate axis) or falls (the maximum value is on the left side of the X-axis coordinate axis)

[0068] b) One extreme point:

[0069] Only the maximum value point is within the X-axis range (the fitted curve rises first and then falls)

[0070] Only the minimum value point is within the X-axis range (the fitted curve falls first and then rises)

[0071] c) Two extreme points:

[0072] x1 < x2 (the fitted curve falls first, then rises, and then falls)

[0073] x1 > x2 (the fitted curve rises first, then falls, and then rises)

[0074] That is, the above calculation obtains two characteristic values: 1. The trend of the fitted curve of the dome temperature; 2. The temperature change slope of the fitted curve of the dome temperature.

[0075] g v =(y2 - y1)÷(x2 - x1)

[0076] where gv is the temperature change slope of the dome, y2 is the maximum value of the temperature of the temperature fitted curve, y1 is the minimum value of the temperature of the temperature fitted curve, x2 is the X coordinate corresponding to the maximum value point, and x1 is the X coordinate corresponding to the minimum value point.

[0077] In a specific embodiment, after the initial combustion period, the temperature rise and fall trend at the current moment is calculated by fitting the curve every minute.

[0078] Due to the characteristics of large lag and slow time-variation of the hot blast stove control system, when making control judgments, we need to combine the temperature rise and fall trends in the previous three minutes, as shown in Figure 3 。

[0079] From Figure 3 It can be seen from finding the extreme value points of the fitted curve in the three time periods that the dome temperature in the previous three minutes before the current moment has been rising continuously.

[0080] In addition, the temperature rise slope in the previous three minutes is obtained:

[0081] G1=(y 1e -y 1s)÷derT

[0082] G2=(y 2e -y 12 )÷derT

[0083] G3=(y 3e -y 3s )÷derT

[0084] Where G1 is the temperature slope for the first minute, y1e is the temperature at the end of the first minute, y1s is the temperature at the beginning of the first minute, G2 is the temperature slope for the second minute, y2e is the temperature at the end of the second minute, y2s is the temperature at the beginning of the second minute, G3 is the temperature slope for the third minute, y3e is the temperature at the end of the third minute, y3s is the temperature at the beginning of the third minute, and derT is the interval time.

[0085] Since G1>G2>G3, we know that... Figure 3 The temperature rise gradually slows down, meaning that the temperature rise slope in the first three minutes can be used to determine the temperature change trend of the vault in the first three minutes.

[0086] In one specific embodiment, a temperature within ±4°C is considered reasonable. A temperature higher than the set temperature by +4°C is considered overheating, and a temperature higher than the set temperature by +8°C is considered exceeding the overheating range.

[0087] If the crown temperature is set to 1320℃, then the reasonable temperature range is [1316℃, 1324℃]; the overheating range is [1324℃, 1328℃]; the overheating range is >= 1328℃; the underheating range is [1312℃, 1316℃]; and the underheating range is <= 1312℃.

[0088] In one specific embodiment, to control the magnitude of the adjustment, we need an air-fuel ratio adjustment step. When the real-time temperature of the dome deviates from the range, the greater the deviation, the larger the air-fuel ratio adjustment must be. Similarly, the greater the change in temperature slope, the larger the air-fuel ratio adjustment must be to control the dome temperature back to normal.

[0089] Based on the temperature change trend of the dome in the previous three minutes and the temperature range of the dome in the previous three minutes, the system adjusts the air-fuel ratio at the current moment according to Table 1 so that the real-time dome temperature returns to normal.

[0090] Table 1 Air-fuel ratio adjustment comparison table

[0091]

[0092] The air-fuel ratio adjustment strategy for the current moment is determined based on the standard (reasonable range) of the dome temperature and the dome temperature trend in the previous three minutes.

[0093] Residual oxygen content generally refers to the proportion of oxygen flow in the exhaust gas pipeline during the combustion process of a hot blast stove to the total exhaust gas flow. It is usually obtained by a zirconium oxide measuring instrument inserted into the exhaust gas pipeline.

[0094] The upper limit of residual oxygen content is the residual oxygen content even if the blast furnace gas and combustion air entering the hot blast stove do not burn.

[0095] exgasO2=(20.5%×Vair)÷(Vgas+Vair)

[0096] Where exgasO2 is the residual oxygen content in the exhaust gas, Vair is the combustion air flow rate, and Vgas is the blast furnace gas flow rate.

[0097] If the air-fuel ratio is 0.8, the residual oxygen content is 9.11%.

[0098] Because the pulverized coal injection process requires the complete combustion of blast furnace gas, the oxygen content (residual oxygen content) in the exhaust gas must be greater than zero. Generally, on-site process requirements specify a residual oxygen content range of 0.2%–0.8%.

[0099] If environmental protection requirements necessitate lowering the dome temperature of the hot blast stove to maintain a low-NOx combustion state, the residual oxygen content will increase significantly, typically reaching 1.5%–2.5%.

[0100] Similarly, when the residual oxygen content in the exhaust gas deviates from the normal range, the greater the deviation, the larger the air-fuel ratio adjustment must be. An embodiment of this invention provides a schematic diagram of the residual oxygen content range, see... Figure 4 .

[0101] Figure 5 This is an example diagram illustrating the trend of the arch temperature change at the previous sampling time, provided in an embodiment of the present invention. Figure 4 It can be seen that the dome temperature was in the overheated range for the first three and first two minutes, but the dome temperature continued to decrease and the slope gradually increased. At the current moment, the dome temperature is in the reasonable range, with an air-fuel ratio of +rS1.

[0102] In one embodiment, the residual oxygen content in the exhaust gas of the hot blast stove is collected. Based on the residual oxygen content in the exhaust gas of the hot blast stove, the trend of the dome temperature change at the previous sampling time is compared with a preset dome temperature standard. The air-fuel ratio of the hot blast stove is adjusted according to the comparison result, including:

[0103] When the residual oxygen content in the exhaust gas in the hot blast stove is lower than the first preset value, the air-fuel ratio is increased;

[0104] The greater the deviation of the residual oxygen content in the exhaust gas from the preset residual oxygen content standard, the greater the air-fuel ratio adjustment.

[0105] In practice, at the end of each minute, a check is performed to determine if there is insufficient gas or air. If this logic is triggered, the insufficient gas / air logic is entered. If the gas flow is insufficient, the actual gas flow is set to the set gas flow, and the air-fuel ratio is adjusted according to the air-fuel ratio adjustment strategy. If the air flow is insufficient, the actual air flow is set to the set air flow, the air-fuel ratio is adjusted according to the air-fuel ratio adjustment strategy, and then the set gas flow is calculated by reversing the steps.

[0106] Both gas and air are insufficient. Calculate the gas flow rate using the following formula:

[0107] Vsetgas = Vgas × IndexDown

[0108] Vsetair = Vsetgas × R0

[0109] Where Vsetgas is the set gas flow rate; Vgas is the actual gas flow rate; IndexDown is the gas drop coefficient; Vsetair is the set air flow rate; and R0 is the calculated air-fuel ratio at the current moment.

[0110] When there is sufficient gas and air, the air-fuel ratio is adjusted mainly based on the temperature range of the dome temperature and the residual oxygen content of the exhaust gas, as mentioned above.

[0111] In one embodiment, the temperature change trend at the current sampling time is calculated, and the temperature change trend at the current sampling time is compared with the dome temperature standard. Based on the comparison result, the air-fuel ratio weight is adjusted, including:

[0112] If the crown temperature does not meet the crown temperature standard at the next sampling time under the temperature change trend of the target period, the weight of the air-fuel ratio calculation factor is modified.

[0113] For example, if the dome temperature is in the overheated range for the first three minutes, and then enters the overheated range from the normal range in the third minute, with the temperature rise rate still increasing, the air-fuel ratio must be increased to increase combustion air in order to bring the dome temperature back to the normal range as quickly as possible. Since the current temperature is already in the overheated range and the rate of increase is still rising, it indicates that the air-fuel ratio adjustment strategy from the previous minute was ineffective. To reduce the real-time dome temperature as quickly as possible, the air-fuel ratio rS5 needs to be increased.

[0114] At the same time, determine the current range of residual oxygen levels, see Figure 6 The current residual oxygen level is 1.55%, which is higher than the set range of 0.2%-0.8%, indicating that the air-fuel ratio is too high, falling into the "too high 2" range. Therefore, the air-fuel ratio needs to be reduced. According to Table 1, the air-fuel ratio rS2 needs to be reduced. This contradicts the previous adjustment target, so it is necessary to introduce a weight to adjust the air-fuel ratio based on the weight.

[0115] The dome temperature one minute after adjusting the air-fuel ratio according to the weighting is shown below. Figure 7 As can be seen, the real-time dome temperature is still in the overheated range. However, since the dome temperature changed from rising to falling after the air-fuel ratio increased by Rc in the previous moment, and the temperature drop slope is greater than the temperature rise slope in the previous moment, the dome temperature of the system is more sensitive to changes in the air-fuel ratio. The air-fuel ratio adjustment in the previous moment was over-adjusted, and the dome temperature overheating air-fuel ratio adjustment weight needs to be adjusted appropriately, from Wr to Wn.

[0116] Wn=Wr-Iwt

[0117] Where Iwt is the weight adjustment coefficient.

[0118] Based on the trend, the temperature of the dome was in the excessively high range for the first three minutes, but the temperature change changed from rising to falling, and the downward slope gradually increased. According to Table 1, the air-fuel ratio adjustment amount is +rS2.

[0119] Given the current residual oxygen level of 1.52%, which is higher than the set range of 0.2% to 0.8%, it indicates that the air-fuel ratio is too high and is still in the excessively high range 2. Therefore, the air-fuel ratio rS2 needs to be reduced.

[0120] This invention also provides a blast furnace hot blast stove dome temperature control device, as described in the following embodiments. Since the principle by which this device solves the problem is similar to the blast furnace hot blast stove dome temperature control method, the implementation of this device can be referred to the implementation of the method, and repeated details will not be elaborated further.

[0121] Figure 8 This is a schematic diagram of the blast furnace hot blast stove dome temperature control device provided in an embodiment of the present invention, as shown below. Figure 8 As shown, the device includes:

[0122] Temperature calculation module 801 is used to collect arch temperature data for multiple cycles using a precise timing function;

[0123] The curve calculation module 802 is used to fit the crown temperature fitting curve of each period based on the crown temperature data of each period, and to find the extreme value solution of the crown temperature fitting curve of each period to obtain the trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve of the target period.

[0124] The trend calculation module 803 is used to calculate the crown temperature change trend of the target period based on the crown temperature fitting curve trend and the temperature change slope of the crown temperature fitting curve, and compare the crown temperature change trend of the target period with the preset crown temperature standard.

[0125] The comparison module 804 is used to collect the residual oxygen content of the exhaust gas at the current sampling time of the hot blast stove, compare the residual oxygen content of the exhaust gas at the current sampling time with the preset residual oxygen content standard, and adjust the air-fuel ratio of the hot blast stove according to the comparison results of the dome temperature and the residual oxygen content.

[0126] The adjustment module 805 is used to repeatedly execute the following steps until the dome temperature after adjusting the air-fuel ratio according to the weight of the modified air-fuel ratio calculation factor meets the dome temperature standard: adjust the air-fuel ratio according to the weight of the air-fuel ratio calculation factor, collect the dome temperature and residual oxygen after adjusting the air-fuel ratio, calculate the temperature change trend of the target period, compare the temperature change trend of the target period with the dome temperature standard, compare the residual oxygen with the exhaust gas residual oxygen standard, and modify the weight of the air-fuel ratio calculation factor according to the comparison results.

[0127] In one embodiment, the curve calculation module 802 is specifically used for:

[0128] The crown temperature data for each period are fitted to obtain the crown temperature data fitting curve for each period.

[0129] The extreme value solutions are obtained by fitting the crown temperature data of each period to the curve, and the characteristic values ​​of each extreme arithmetic solution are obtained.

[0130] The trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve are determined based on the characteristic values.

[0131] In one embodiment, the comparison module 804 is specifically used for:

[0132] When the residual oxygen content in the exhaust gas in the hot blast stove is lower than the first preset value, the air-fuel ratio is increased;

[0133] The greater the deviation of the residual oxygen content in the exhaust gas from the preset residual oxygen content standard, the greater the air-fuel ratio adjustment.

[0134] In one embodiment, the adjustment module 805 is specifically used for:

[0135] If the crown temperature does not meet the crown temperature standard at the next sampling time under the temperature change trend of the target period, the weight of the air-fuel ratio calculation factor is modified.

[0136] Based on the aforementioned inventive concept, such as Figure 9 As shown, the present invention also proposes a computer device 900, including a memory 910, a processor 920, and a computer program 930 stored in the memory 910 and executable on the processor 920. When the processor 920 executes the computer program 930, it implements the aforementioned method for controlling the temperature of the blast furnace hot blast stove dome.

[0137] This invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for controlling the temperature of the blast furnace hot blast stove dome.

[0138] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-described method for controlling the temperature of the blast furnace hot blast stove dome.

[0139] In summary, in this embodiment of the invention, a precise timing function is used to collect arch temperature data for multiple cycles; arch temperature fitting curves for each cycle are fitted based on the arch temperature data for each cycle, and extreme value solutions are obtained for the arch temperature fitting curves for each cycle to obtain the trend and slope of the arch temperature fitting curve for the target cycle; based on the trend and slope of the arch temperature fitting curve for the target cycle, the arch temperature change trend for the target cycle is calculated, and the arch temperature change trend for the target cycle is compared with a preset arch temperature standard; the residual oxygen content of the exhaust gas at the current sampling moment of the hot air furnace is collected, and the current... The residual oxygen content in the exhaust gas at the previous sampling time is compared with the preset standard for residual oxygen content in the exhaust gas. The air-fuel ratio of the hot blast stove is adjusted based on the comparison results of the dome temperature and the residual oxygen content. The following steps are repeated until the dome temperature after adjusting the air-fuel ratio according to the weight of the modified air-fuel ratio calculation factor meets the dome temperature standard: Adjust the air-fuel ratio according to the weight of the air-fuel ratio calculation factor, collect the dome temperature and residual oxygen content after the adjustment, calculate the temperature change trend for the target period, compare the temperature change trend for the target period with the dome temperature standard, compare the residual oxygen content with the standard for residual oxygen content in the exhaust gas, and modify the weight of the air-fuel ratio calculation factor based on the comparison results. In this way, by judging the past trend of the dome temperature and analyzing the feedback effect in real time, the direction of air-fuel ratio adjustment is determined, and the air-fuel ratio is precisely controlled to achieve the goal of precisely controlling the dome temperature. This ensures that the hot blast stove's combustion state reaches its optimal level, effectively guaranteeing blast furnace production and operation.

[0140] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0141] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0142] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0143] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0144] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling the temperature of the dome of a blast furnace hot blast stove, characterized in that, include: The arch temperature data for multiple cycles is collected using a precise timing function; Based on the crown temperature data of each period, fit the crown temperature fitting curve of each period, find the extreme value solution of the crown temperature fitting curve of each period, and obtain the trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve of the target period. Based on the trend of the crown temperature fitting curve and the slope of the crown temperature fitting curve for the target period, the crown temperature change trend for the target period is calculated, and the crown temperature change trend for the target period is compared with the preset crown temperature standard. Collect the residual oxygen content of the exhaust gas at the current sampling time of the hot blast stove, compare the residual oxygen content of the exhaust gas at the current sampling time with the preset residual oxygen content standard, and adjust the air-fuel ratio of the hot blast stove according to the comparison results of the dome temperature and the residual oxygen content. Repeat the following steps until the dome temperature after adjusting the air-fuel ratio according to the weight of the modified air-fuel ratio calculation factor meets the dome temperature standard: Adjust the air-fuel ratio according to the weight of the air-fuel ratio calculation factor, collect the dome temperature and residual oxygen after adjusting the air-fuel ratio, calculate the temperature change trend of the target period, compare the temperature change trend of the target period with the dome temperature standard, compare the residual oxygen with the exhaust gas residual oxygen standard, and modify the weight of the air-fuel ratio calculation factor according to the comparison results.

2. The method as described in claim 1, characterized in that, Based on the crown temperature data for each period, fit the crown temperature curve for each period, and calculate the extreme value solution for the crown temperature fitting curve for each period to obtain the trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve for the target period, including: The crown temperature data for each period are fitted to obtain the crown temperature data fitting curve for each period. The extreme value solutions are obtained by fitting the crown temperature data of each period to the curve, and the characteristic values ​​of each extreme arithmetic solution are obtained. The trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve are determined based on the characteristic values.

3. The method as described in claim 1, characterized in that, The air-fuel ratio of the hot blast stove is adjusted based on the comparison results of the dome temperature and the residual oxygen content in the exhaust gas, including: When the residual oxygen content in the exhaust gas in the hot blast stove is lower than the first preset value, the air-fuel ratio is increased; The greater the deviation of the residual oxygen content in the exhaust gas from the preset residual oxygen content standard, the greater the air-fuel ratio adjustment.

4. The method as described in claim 1, characterized in that, Calculate the temperature change trend for the target period, compare it with the dome temperature standard, compare the residual oxygen content with the exhaust gas residual oxygen standard, and adjust the air-fuel ratio weight based on the comparison results, including: If the crown temperature does not meet the crown temperature standard at the next sampling time under the temperature change trend of the target period, the weight of the air-fuel ratio calculation factor is modified.

5. A temperature control device for the dome of a blast furnace hot blast stove, characterized in that, include: The temperature calculation module is used to collect vault temperature data over multiple cycles using a precise timing function; The curve calculation module is used to fit the crown temperature fitting curve for each period based on the crown temperature data for each period, and to find the extreme value solution for the crown temperature fitting curve for each period to obtain the trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve for the target period. The trend calculation module is used to calculate the crown temperature change trend of the target period based on the crown temperature fitting curve trend and the temperature change slope of the crown temperature fitting curve, and compare the crown temperature change trend of the target period with the preset crown temperature standard. The comparison module is used to collect the residual oxygen content of the exhaust gas at the current sampling time of the hot blast stove, compare the residual oxygen content of the exhaust gas at the current sampling time with the preset residual oxygen content standard, and adjust the air-fuel ratio of the hot blast stove according to the comparison results of the dome temperature and the residual oxygen content. The adjustment module is used to repeatedly execute the following steps until the dome temperature after adjusting the air-fuel ratio according to the weight of the modified air-fuel ratio calculation factor meets the dome temperature standard: adjust the air-fuel ratio according to the weight of the air-fuel ratio calculation factor, collect the dome temperature and residual oxygen after adjusting the air-fuel ratio, calculate the temperature change trend of the target period, compare the temperature change trend of the target period with the dome temperature standard, compare the residual oxygen with the exhaust gas residual oxygen standard, and modify the weight of the air-fuel ratio calculation factor according to the comparison results.

6. The apparatus as claimed in claim 5, characterized in that, The curve calculation module is specifically used for: The crown temperature data for each period are fitted to obtain the crown temperature data fitting curve for each period. The extreme value solutions are obtained by fitting the crown temperature data of each period to the curve, and the characteristic values ​​of each extreme arithmetic solution are obtained. The trend of the crown temperature fitting curve and the slope of the temperature change of the crown temperature fitting curve are determined based on the characteristic values.

7. The apparatus as claimed in claim 5, characterized in that, The comparison module is specifically used for: When the residual oxygen content in the exhaust gas in the hot blast stove is lower than the first preset value, the air-fuel ratio is increased; The greater the deviation of the residual oxygen content in the exhaust gas from the preset residual oxygen content standard, the greater the air-fuel ratio adjustment.

8. The apparatus as claimed in claim 5, characterized in that, The adjustment module is specifically used for: If the crown temperature does not meet the crown temperature standard at the next sampling time under the temperature change trend of the target period, the weight of the air-fuel ratio calculation factor is modified.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 4.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1 to 4.

11. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method of any one of claims 1 to 4.

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