Automatic control method and device for drying furnace of blast furnace coal injection system

Abstract

The present invention provides an automatic control method and device for a drying furnace in a blast furnace coal injection system, belonging to the technical field of blast furnace coal injection pulverizing technology. The present invention includes detecting a coke oven gas pipeline; determining an ignition program based on the detection result of the coke oven gas pipeline; obtaining a first flow rate, a first opening, a first temperature, a second temperature, a third temperature, and a first pressure; determining a combustion program based on the characteristic relationship of the regulating valve between the first opening and the first flow rate, so that the first temperature is within a temperature threshold range; determining the opening of the exhaust gas induced draft fan damper actuator based on the first pressure, so that the first pressure is within a drying furnace hearth pressure threshold range; controlling the second temperature within a preset value range of the pulverizer inlet temperature and the third temperature within a preset value range of the pulverizer outlet temperature according to the current combustion program. The present invention avoids system fluctuations caused by manual operation and improves the quality of pulverized coal produced by the pulverizing system.

Description

Technical Field

[0001] The present invention relates to the technical field of blast furnace coal injection systems, and in particular to an automatic control method and device for a drying furnace of a blast furnace coal injection system. Background Art

[0002] In the iron and steel industry, blast furnace coal injection (BFI) is the most efficient technology for providing fuel for blast furnace ironmaking. This process is a logical choice for advancements in blast furnace smelting technology. It not only reduces coke consumption, improves economic efficiency, and maintains a stable and continuous flow of injected coal, but also serves as a regulatory tool to improve blast furnace conditions.

[0003] To ensure a stable and continuous coal injection flow, in addition to adjusting the injection system for stable control, the fineness, temperature, and moisture content of the pulverized coal are also important factors. Currently, the pulverizing process primarily involves mixing the high-temperature flue gas generated by the combustion of blast furnace gas and combustion air in a drying furnace with the exhaust gas from the hot blast furnace to form an inert hot gas suitable for drying the pulverized coal. However, the primary method for controlling the drying furnace area is still remote manual control. This results in frequent fluctuations in the drying furnace temperature and pressure due to the influence of multiple variables, affecting the stable operation of the pulverizing system.

[0004] For this problem, experienced operators who are familiar with the relevant adjustment methods can make the fluctuations smaller and controllable; however, operators with less operating experience basically do not have the ability to ignite the furnace, control the furnace temperature, and control the furnace pressure, which results in the pulverized coal having high humidity and high viscosity, causing poor blowing during the pneumatic conveying process, and even blocking the pipe and gun, seriously affecting the stable operation of the blast furnace and causing certain economic losses.

[0005] Therefore, in order to improve the stable injection capability of the coal injection system, the automatic stable adjustment of the pulverizing system is particularly important. Accurately controlling the relevant equipment and valves in the drying furnace area and improving the automatic control capability of the drying furnace have become current issues that need to be addressed. Summary of the Invention

[0006] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a method and device for automatically controlling a drying furnace in a blast furnace coal injection system, so as to solve at least one of the above-mentioned technical problems.

[0007] In a first aspect, the present invention provides a method for automatically controlling a drying furnace in a blast furnace coal injection system, comprising:

[0008] Detection of coke oven gas pipelines;

[0009] determining an ignition procedure according to the detection result of the coke oven gas pipeline;

[0010] Obtain a first flow rate, a first opening, a first temperature, a second temperature, a third temperature, and a first pressure, wherein the first flow rate is the real-time flow rate of blast furnace gas, the first opening is the real-time opening of the blast furnace gas flow control valve, the first temperature is the real-time temperature of the drying furnace hearth, the second temperature is the real-time temperature of the coal mill inlet, the third temperature is the real-time temperature of the coal mill outlet, and the first pressure is the real-time pressure of the drying furnace hearth;

[0011] determining a combustion program according to a correspondence between the first opening degree and the first flow rate so that the first temperature is within a temperature threshold range;

[0012] Determining the opening of the exhaust gas induced draft fan damper actuator according to the first pressure so that the first pressure is within a threshold range of the drying furnace hearth pressure;

[0013] According to the current combustion program, the second temperature is controlled within a preset value range of the coal mill inlet temperature, and the third temperature is controlled within a preset value range of the coal mill outlet temperature.

[0014] In one embodiment of the present invention, determining the ignition procedure according to the detection result of the coke oven gas pipeline includes:

[0015] The ignition program includes a first ignition program and a second ignition program;

[0016] When no coke oven gas pipeline is detected, the first ignition program is selected and blast furnace gas is input to complete ignition;

[0017] When the presence of a coke oven gas pipeline is detected, the second ignition procedure is selected and coke oven gas is input to complete ignition.

[0018] In one embodiment of the present invention, determining the combustion program according to the correspondence between the first opening and the first flow rate so that the first temperature is within a temperature threshold range includes:

[0019] The combustion program includes a first combustion program;

[0020] When the corresponding relationship conforms to the valve flow characteristic curve, selecting the first combustion program;

[0021] The opening of the blast furnace gas flow regulating valve is adjusted by the first controller to control the flow of blast furnace gas entering the drying furnace so that the first temperature is within the temperature threshold range.

[0022] In one embodiment of the present invention, determining the combustion program according to the correspondence between the first opening and the first flow rate so that the first temperature is within a temperature threshold range includes:

[0023] The combustion program includes a second combustion program;

[0024] When the corresponding relationship does not conform to the valve flow characteristic curve, selecting the second combustion program;

[0025] The opening of the blast furnace gas flow regulating valve is adjusted by the second controller to control the flow of blast furnace gas entering the drying furnace so that the first temperature is within the temperature threshold range.

[0026] In one embodiment of the present invention, determining the combustion program according to the correspondence between the first opening and the first flow rate so that the first temperature is within a temperature threshold range includes:

[0027] When in the heat preservation stage, the temperature thresholds include the heat preservation temperature of the drying furnace and the upper limit of the heat dissipation temperature of the drying furnace;

[0028] When in the warm grinding stage, the temperature thresholds include an upper temperature limit of the drying furnace warm grinding and a lower temperature limit of the drying furnace warm grinding.

[0029] In one embodiment of the present invention, controlling the second temperature within a preset value range of the coal mill inlet temperature and controlling the third temperature within a preset value range of the coal mill outlet temperature according to the current combustion program includes:

[0030] When the current combustion model is the first combustion program, the flow rate of the blast furnace gas entering the drying furnace is controlled by the first controller to control the second temperature within a preset range of a coal mill inlet temperature and the third temperature within a preset range of a coal mill outlet temperature;

[0031] When the current combustion model is the second combustion program, the blast furnace gas flow entering the drying furnace is controlled by the second controller to control the second temperature within the preset value range of the pulverizer inlet temperature and the third temperature within the preset value range of the pulverizer outlet temperature.

[0032] In one embodiment of the present invention, when the current combustion model is the first combustion program, after controlling the blast furnace gas flow rate entering the drying furnace by the first controller to control the second temperature within a preset range of a coal mill inlet temperature and the third temperature within a preset range of a coal mill outlet temperature, the method further includes:

[0033] The pulverizing capacity is divided into N pulverizing levels according to the pulverizing capacity of the equipment, and each pulverizing level is provided with a corresponding blast furnace gas flow rate;

[0034] Obtaining a first pulverizing amount, where the first pulverizing amount is a real-time pulverizing amount of a blast furnace pulverizing system;

[0035] determining the milling grade according to the first milling amount;

[0036] The blast furnace gas flow rate adjusted by the first controller is set as the blast furnace gas flow rate setting flow rate of the pulverizing grade, and is used as the initial blast furnace gas target flow rate for the next pulverizing grade.

[0037] In one embodiment of the present invention, after determining the ignition program according to the detection result of the coke oven gas pipeline, the method further includes:

[0038] Detecting the display light of the flame detector; if the display light is detected to be on, the ignition is successful and the combustion procedure is implemented;

[0039] If the display light is not detected to be on, the ignition fails, and the ignition procedure is repeated until the display light is detected to be on.

[0040] In a second aspect, the present invention further provides an automatic control device for a drying furnace of a blast furnace coal injection system, comprising:

[0041] Detection module, used to detect the presence of coke oven gas pipelines;

[0042] an ignition module, which determines an ignition procedure according to the detection result of the coke oven gas pipeline;

[0043] An acquisition module, configured to acquire a first flow rate, a first opening degree, a first temperature, a first pressure, and a first powder production amount;

[0044] a combustion module, determining a combustion program according to a correspondence between the first flow rate and the first opening;

[0045] A control module is used to control the first temperature to be within a temperature threshold range, control the opening of the exhaust draft fan damper actuator so that the first pressure is within a drying furnace furnace pressure threshold range, control the second temperature to be within a preset value range of the pulverizer inlet temperature, and control the third temperature to be within a preset value range of the pulverizer outlet temperature.

[0046] Beneficial effects of the present invention:

[0047] The present invention provides a method and device for automatically controlling a drying furnace in a blast furnace coal injection system. The method completes the ignition and combustion of the drying furnace through an ignition program and a combustion program, and controls the furnace pressure of the drying furnace by controlling the opening of an exhaust gas induced draft fan damper regulating valve. The method can quickly and accurately adjust the furnace temperature and furnace pressure of the drying furnace, avoids system fluctuations caused by manual operation, and realizes the automation of blast furnace gas combustion. Moreover, by obtaining a first pulverizing amount and determining a set flow rate of blast furnace gas, data is provided for subsequent pulverizing, thereby improving the reliability of coal injection and thereby improving the quality of pulverized coal produced by the pulverizing system.

[0048] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present invention, and together with the specification, are used to explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and it is clear that a person skilled in the art can derive other drawings based on these drawings without inventive effort. In the drawings:

[0050] Figure 1 An equipment schematic diagram of a drying furnace area shown in an exemplary embodiment of the present invention;

[0051] Figure 2 A flow chart of an automatic control method for a drying furnace in a blast furnace coal injection system is shown in an exemplary embodiment of the present invention;

[0052] Figure 3 A valve flow characteristic curve shown in an exemplary embodiment of the present invention;

[0053] Figure 4 A block diagram of an automatic control device for a drying furnace in a blast furnace coal injection system is shown in an exemplary embodiment of the present invention.

[0054] Part Number Description

[0055] 1-Drying furnace; 2-Blast furnace gas flow cut-off valve; 3-Blast furnace gas flow regulating valve; 4-Coke oven gas flow cut-off valve; 5-Coke oven gas flow regulating valve; 6-Combustion-supporting fan; 7-Drying furnace vent valve; 8-Exhaust gas induced draft fan damper actuator; 9-Combustion-supporting air flow regulating valve; 10-Exhaust gas induced draft fan.

[0056] Specific implementation procedures

[0057] The following will describe the implementation procedures of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art will readily understand the other advantages and effects of the present invention from the contents disclosed in this specification. The present invention may also be implemented or applied through different specific implementation procedures, and the details in this specification may be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are merely illustrative of the present invention and are not intended to limit the scope of protection of the present invention.

[0058] It should be noted that the diagrams provided in the following embodiments are merely schematic illustrations of the basic concept of the present invention. Therefore, the diagrams only show components relevant to the present invention and are not drawn according to the number, shape, and size of components in actual implementation. In actual implementation, the type, quantity, and proportion of each component may be changed arbitrarily, and the component layout may also be more complex.

[0059] In the following description, numerous details are discussed to provide a more thorough explanation of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the embodiments of the present invention may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring the embodiments of the present invention.

[0060] See also Figure 1 , Figure 1 FIG. 1 is a schematic diagram of an exemplary embodiment of the present invention showing a drying furnace area. Figure 1 As shown, the drying furnace 1 is connected to a blast furnace gas pipeline and a coking coal gas pipeline. The blast furnace gas pipeline is connected in sequence to a blast furnace gas flow cutoff valve 2 and a blast furnace gas flow regulating valve 3, while the coking coal gas pipeline is connected in sequence to a coke oven gas flow cutoff valve 4 and a coke oven gas flow regulating valve 5. The drying furnace 1 is also connected to a combustion-supporting blower 6, a drying furnace vent valve 7, and an exhaust gas induced draft fan damper actuator 8. A combustion-supporting air flow regulating valve 9 is connected between the combustion-supporting blower 6 and the drying furnace 1. One end of the exhaust gas induced draft fan damper actuator 8 is connected to the hot blast furnace exhaust pipe, and the other end is connected to an exhaust gas induced draft fan 10, which is located between the hot blast furnace and the drying furnace 1.

[0061] When the drying furnace 1 is in the ignition stage, the drying furnace vent valve 7 is opened, and the ignition procedure is determined by detecting whether there is a coking coal gas pipeline to ignite the drying furnace 1. When the drying furnace 1 is in the insulation stage, the opening of the blast furnace gas flow control valve 3 is adjusted to ensure that the first temperature is within the temperature threshold range. When the drying furnace 1 is in the warm grinding stage, the drying furnace vent valve 7 is closed, and the opening of the blast furnace gas flow control valve 3 is adjusted to ensure that the first temperature is within the temperature threshold range. When the drying furnace 1 is in the coal baking stage, the exhaust gas draft fan damper actuator 8 is opened and the exhaust gas draft fan 10 is started. The opening of the exhaust gas draft fan damper actuator 8 is adjusted to ensure that the first pressure is within the drying furnace furnace pressure threshold range.

[0062] See also Figure 2 , Figure 2 This is a flow chart of an automatic control method for a blast furnace coal injection system drying furnace according to an exemplary embodiment of the present application. Figure 1As shown, in an exemplary embodiment, the automatic control method of the drying furnace of the blast furnace coal injection system includes at least steps S210 to S270, which are described in detail as follows:

[0063] Step S210: Detect the coke oven gas pipeline.

[0064] In one embodiment of the present invention, the coke oven gas pipeline can be confirmed by manual inspection, can be detected by sensors, and can also be detected by image recognition.

[0065] Step S220: determining an ignition procedure based on the detection result of the coke oven gas pipeline.

[0066] It should be noted that the ignition program includes a first ignition program and a second ignition program.

[0067] In one embodiment of the present invention, when it is detected that there is no coke oven gas pipeline, the first ignition program is selected and blast furnace gas is input to complete the ignition.

[0068] Specifically, the first ignition program is to control the drying furnace system to automatically start, control the drying furnace release valve 7 to open in place; after obtaining the drying furnace release valve 7 open in place signal, the blast furnace gas flow regulating valve 3 automatically opens to the set initial opening V 2Init , the combustion air flow regulating valve 9 automatically opens to the set initial opening V 1Init , and start the combustion-supporting blower 6. After a 30-second delay for the combustion-supporting blower 6 to operate normally, the blast furnace gas flow cutoff valve 2 is opened, allowing the gas and combustion-supporting air to enter the combustion chamber of the drying furnace 1 and mix. After a 30-second delay for the gas and combustion-supporting air to mix, the ignition gun automatically advances and ignites. The normal operating time of the combustion-supporting blower 6 and the gas and combustion-supporting air mixing time can be adjusted according to specific operating conditions.

[0069] It should be noted that after the ignition is completed, the combustion air flow rate (F 2Act *α) Real-time feedback and PID tracking. Among them, F 2Act represents the actual blast furnace gas flow rate, and α represents the combustion ratio.

[0070] In one embodiment of the present invention, when the presence of a coke oven gas pipeline is detected, the second ignition program is selected and coke oven gas is input to complete ignition.

[0071] Specifically, the second ignition program is to control the drying furnace 1 to start automatically, and then control the drying furnace release valve 7 to open in place; after obtaining the drying furnace release valve 7 open in place signal, the combustion air flow regulating valve 9 automatically opens to the set initial opening V 1Init , the coke oven gas flow regulating valve 5 is opened to the set initial opening V 5Init, and start the combustion-supporting fan 6; after the combustion-supporting fan 6 is delayed for 30 seconds during normal operation, open the coke oven gas flow cut-off valve 4, at which time the coke oven gas and combustion-supporting air enter the drying furnace 1 combustion chamber and mix; the ignition gun automatically advances and ignites.

[0072] In one embodiment of the present invention, after determining the ignition program according to the detection result of the coke oven gas pipeline in step S220, the process may include steps S221 to S223.

[0073] Step S221, detecting the display light of the flame detector.

[0074] In one embodiment of the present invention, the display light of the flame detector can be confirmed by human inspection, can be detected by a sensor, and can also be detected by image recognition.

[0075] Step S222: If the display light of the flame detector is detected to be on, the ignition is successful and the combustion process is implemented.

[0076] In one embodiment of the present invention, when the display light of the flame detector is detected to be on, it indicates that the ignition gun has been ignited successfully and the combustion program can be implemented to enter the heat preservation stage.

[0077] It should be noted that if the second ignition procedure is implemented, after the ignition is successful, the blast furnace gas flow regulating valve 3 automatically opens to the set initial opening V 2Init , and open the blast furnace gas flow cut-off valve 2, then close the coke oven gas flow regulating valve 5 and the coke oven gas flow cut-off valve 4. The combustion air flow (F 2Act *α) Real-time feedback and PID tracking.

[0078] Step S223: If the indicator light of the flame detector is not detected to be on, the ignition fails, and the ignition procedure is repeated until the indicator light of the flame detector is detected to be on.

[0079] In one embodiment of the present invention, when the display light of the flame detector is not detected to be on, it indicates that the ignition gun has failed to ignite, and the ignition procedure needs to be repeated until the ignition gun ignites successfully and the display light of the flame detector is on.

[0080] In another embodiment of the present invention, when the flame detector indicator light is not on, the success of the ignition gun can be determined by detecting the temperature of the drying furnace 1. If the temperature of the drying furnace 1 is greater than 400°C, it indicates that the ignition gun has successfully ignited; if the temperature of the drying furnace 1 is less than 400°C, it indicates that the ignition gun has failed to ignite.

[0081] Step S230: Acquire a first flow rate, a first opening degree, a first temperature, a second temperature, a third temperature, and a first pressure.

[0082] It should be noted that the first flow rate is the real-time flow rate of blast furnace gas, the first opening is the real-time opening of the blast furnace gas flow regulating valve, the first temperature is the real-time temperature of the drying furnace hearth, the second temperature is the real-time temperature of the pulverizer inlet, the third temperature is the real-time temperature of the pulverizer outlet, and the first pressure is the real-time pressure of the drying furnace hearth.

[0083] In one embodiment of the present invention, the first flow rate can be fed back through a flow meter, the first opening degree can be fed back through a displacement sensor, the first temperature, the second temperature and the third temperature can be obtained by a temperature sensor, and the first pressure can be obtained by a micro differential pressure transmitter.

[0084] For example, the first flow rate, the first opening degree, the first temperature, the second temperature, the third temperature and the first pressure may be acquired every 1 second, and may also be adjusted according to actual working conditions.

[0085] Step S240 : determining a combustion program according to the corresponding relationship between the first opening degree and the first flow rate, so that the first temperature is within a temperature threshold range.

[0086] See also Figure 3 , Figure 3 This is a valve flow characteristic curve shown in an exemplary embodiment of the present application. Figure 3 As shown, in one embodiment of the present invention, during the debugging process, the opening of the blast furnace gas flow control valve 3 and the blast furnace gas flow passing through the opening are obtained, and it is determined whether the corresponding relationship between the two conforms to the valve flow characteristic curve, and then a combustion program is selected, and the combustion program is used as the recommended combustion program for the subsequent combustion control of the drying furnace 1.

[0087] In another embodiment of the present invention, during operation, when the blast furnace gas flow rate regulating valve 3 has the same opening, when the flow rate of the blast furnace gas passing through different time periods at the opening is consistent, it indicates that the correspondence between the first opening and the first flow rate conforms to the valve flow characteristic curve; when the flow rate of the blast furnace gas passing through different time periods at the opening is inconsistent, such as the deviation of the flow rate of the blast furnace gas passing through different time periods at the opening reaches or exceeds 10%, it indicates that the correspondence between the first opening and the first flow rate does not conform to the valve flow characteristic curve.

[0088] In another embodiment of the present invention, during operation, when the valve opening of the blast furnace gas flow control valve 3 cannot cover the corresponding target range in the valve flow characteristic curve within the range of 0-100%, it indicates that the correspondence between the first opening and the first flow does not conform to the valve flow characteristic curve.

[0089] It should be noted that during operation, when the blast furnace gas flow regulating valve 3 has the same opening, when the blast furnace gas flow rate passing through different time periods at the opening is inconsistent, but the deviation of the blast furnace gas flow rate passing through different time periods at the opening is between 0-10%, it is determined that the correspondence between the first opening and the first flow rate conforms to the valve flow characteristic curve.

[0090] Specifically, the combustion program includes a first combustion program and a second combustion program.

[0091] It should be noted that after the drying furnace 1 is successfully ignited, it will enter the insulation stage, warm grinding stage and coal drying stage in sequence. Among them, the insulation stage, warm grinding stage and coal drying stage all involve gas combustion, so each of the above stages involves the selection of combustion program.

[0092] Once the combustion program is determined for the holding phase, the warm-up phase can continue with the holding phase's combustion program, or a new combustion program can be selected. The subsequent coal drying phase can follow the same plan. Furthermore, the combustion program can be switched midway through each phase, either manually or automatically.

[0093] In one embodiment of the present invention, when the corresponding relationship between the first opening and the first flow rate conforms to the valve flow characteristic curve, the first combustion program is selected.

[0094] Specifically, when the combustion program is determined to be the first combustion program, the initial blast furnace gas flow rate F of the blast furnace gas can be tracked by a flow meter. 2Init The first controller is used to adjust the opening of the blast furnace gas flow regulating valve 3 to control the flow of blast furnace gas entering the drying furnace 1 so that the first temperature is within the temperature threshold range. The first controller is a PID regulation controller.

[0095] In one embodiment of the present invention, when the drying furnace 1 is successfully ignited and just enters the insulation stage, the blast furnace gas flow rate entering the drying furnace 1 is the initial blast furnace gas flow rate F 2Init , monitor the drying furnace hearth temperature and the drying furnace exhaust temperature. After 30 seconds, the first temperature is compared with the temperature threshold, and the opening of the blast furnace gas flow regulating valve 3 is adjusted according to the comparison result.

[0096] Among them, when in the insulation stage, the temperature threshold includes the drying furnace insulation temperature T Hold And the upper limit of the drying furnace temperature T 4H .

[0097] When T Act <T HoldWhen , the first controller controls the blast furnace gas flow regulating valve 3 to increase the valve opening corresponding to a blast furnace gas flow regulating gradient in the valve flow characteristic curve to increase the drying furnace hearth temperature, which can be expressed by the following formula:

[0098] F 2Set =F 2Init +F 2△ ;

[0099] When T Act ≥T Hold , but T 4Act ≤T 4H When , the first controller does not adjust the blast furnace gas flow regulating valve 3;

[0100] When T Act ≥T Hold , and T 4Act >T 4H When , the first controller controls the blast furnace gas flow regulating valve 3 to reduce the valve opening corresponding to a blast furnace gas flow regulating gradient in the valve flow characteristic curve, so as to reduce the drying furnace hearth temperature, which can be expressed by the following formula:

[0101] F 2Set =F 2Init -F 2△ ;

[0102] Among them, T Act Represents the first temperature; T Hold Indicates the holding temperature of the drying furnace; T 4Act Indicates the actual emission temperature of the drying furnace; T 4H Indicates the upper limit of the drying furnace's heat release temperature; F 2Iint Indicates the initial blast furnace gas flow rate; F 2△ Indicates the blast furnace gas flow regulation gradient; F 2Set Indicates the blast furnace gas flow rate 30 seconds after entering the insulation stage.

[0103] In one embodiment of the present invention, when entering the warm grinding stage, the first temperature is compared with the temperature threshold, and the opening of the blast furnace gas flow regulating valve 3 is adjusted according to the comparison result.

[0104] It should be noted that after entering the warm-up phase, due to the negative pressure created by the controlled activation of the main exhaust fan, hot air begins to enter the coal mill to warm it up. At this time, the drying furnace bleed valve 7 is closed. During the warm-up phase, the temperature thresholds include the upper and lower warm-up temperature limits of the drying furnace.

[0105] When T Act <(T Hold -T △), the first controller controls the blast furnace gas flow regulating valve 3 to increase the valve opening corresponding to a blast furnace gas flow regulating gradient in the valve flow characteristic curve to increase the drying furnace hearth temperature, which can be expressed by the following formula:

[0106] F 2Set =F 2Set '+F 2△ ;

[0107] When T Act >(T Hold +T △ ), the first controller controls the blast furnace gas flow regulating valve 3 to reduce the valve opening corresponding to the blast furnace gas flow regulating gradient in the valve flow characteristic curve to reduce the drying furnace hearth temperature, which can be expressed by the following formula:

[0108] F 2Set =F 2Set '-F 2△ ;

[0109] When (T Hold -T △ )≤T Act ≤(T Hold +T △ ), the first controller does not adjust the blast furnace gas flow regulating valve 3.

[0110] Among them, (T Hold -T △ ) represents the lower limit of the warm grinding temperature of the drying furnace; (T Hold +T △ ) represents the upper limit of the warm grinding temperature of the drying furnace; T △ Indicates the temperature difference between the drying furnace and the grinding mill; F 2Set " indicates the current blast furnace gas flow rate; F 2Set ' indicates F 2Set ” Blast furnace gas flow rate in the first 30 seconds.

[0111] In one embodiment of the present invention, when the corresponding relationship between the first opening and the first flow rate does not conform to the valve flow rate characteristic curve, the second combustion program is selected.

[0112] Specifically, when the combustion program is determined to be the second combustion program, the second controller adjusts the opening of the blast furnace gas flow regulating valve 3 to control the flow of blast furnace gas entering the drying furnace 1 so that the first temperature is within the temperature threshold range. The second controller is a blast furnace gas flow regulating valve opening controller.

[0113] It should be noted that the second combustion program cancels the tracking of the blast furnace gas flow rate by PID, and controls the valve position of the blast furnace gas flow regulating valve 3 in a periodic quantitative manner.

[0114] In one embodiment of the present invention, when the drying furnace 1 is successfully ignited and enters the insulation stage, the valve position of the blast furnace gas flow regulating valve 3 of the drying furnace 1 is the initial valve position V 2Iint , and monitor the drying furnace hearth temperature and the drying furnace exhaust temperature. After 30 seconds, the first temperature is compared with the temperature threshold, and the opening of the blast furnace gas flow regulating valve 3 is adjusted according to the comparison result.

[0115] Among them, when in the insulation stage, the temperature threshold includes the drying furnace insulation temperature T Hold And the upper limit of the drying furnace temperature T 4H .

[0116] When T Act <T Hold When , the second controller controls the opening of the blast furnace gas flow regulating valve 3 to increase the valve position adjustment gradient of the blast furnace gas flow regulating valve 3 to increase the furnace temperature of the drying furnace, which can be expressed by the following formula:

[0117] V 2Set =V 2Init +V 2△ ;

[0118] When T Act ≥T Hold , but T 4Act ≤T 4H When , the second controller does not adjust the blast furnace gas flow regulating valve 3;

[0119] When T Act ≥T Hold , and T 4Act >T 4H When , the second controller controls the blast furnace gas flow regulating valve 3 to reduce the valve position adjustment gradient of the blast furnace gas flow regulating valve 3 to reduce the drying furnace hearth temperature, which can be expressed by the following formula:

[0120] V 2Set =V 2Init -V 2△ ;

[0121] Among them, T Act Represents the first temperature; T Hold Indicates the holding temperature of the drying furnace; T 4Act Indicates the actual emission temperature of the drying furnace; T 4H Indicates the upper limit of the drying furnace's heat release temperature; V 2Iint Indicates the initial valve position of the blast furnace gas flow regulating valve 3; V 2△ V represents the valve position adjustment gradient of the blast furnace gas flow control valve 3; 2Set Indicates the valve position of blast furnace gas flow control valve 3 30 seconds after entering the insulation stage.

[0122] In one embodiment of the present invention, after entering the warm grinding stage, the first temperature is compared with the temperature threshold, and the opening of the blast furnace gas flow regulating valve 3 is adjusted according to the comparison result.

[0123] It should be noted that after entering the warm-up phase, due to the negative pressure created by the controlled activation of the main exhaust fan, hot air begins to enter the coal mill area to warm the coal mill. At this time, the drying furnace bleed valve 7 is closed. During the warm-up phase, the temperature thresholds include the upper and lower warm-up temperature limits of the drying furnace.

[0124] When T Act <(T Hold -T △ ), the second controller controls the opening of the blast furnace gas flow regulating valve 3 to increase the valve position adjustment gradient of the blast furnace gas flow regulating valve 3 to increase the furnace temperature of the drying furnace, which can be expressed by the following formula:

[0125] V 2Set ”=V 2Set '+V 2△ ;

[0126] When T Act >(T Hold +T △ ), the second controller controls the opening of the blast furnace gas flow regulating valve 3 to reduce the valve position adjustment gradient of the blast furnace gas flow regulating valve 3 to reduce the furnace temperature of the drying furnace, which can be expressed by the following formula:

[0127] V 2Set ”=V 2Set '-V 2△ ;

[0128] When (T Hold -T △ )≤T Act ≤(T Hold +T △ ), the second controller does not adjust the blast furnace gas flow regulating valve 3.

[0129] Among them, (T Hold -T △ ) represents the lower limit of the warm grinding temperature of the drying furnace; (T Hold +T △ ) represents the upper limit of the warm grinding temperature of the drying furnace; T △ Indicates the temperature difference between the drying furnace and the grinding mill; V 2Set " indicates the current valve position of the blast furnace gas flow regulating valve 3; V 2Set ' indicates V 2Set ”The valve position of blast furnace gas flow control valve 3 in the first 30 seconds.

[0130] Step S250: determining the opening of the exhaust gas induced draft fan damper actuator 8 according to the first pressure, so that the first pressure is within a threshold range of the drying furnace hearth pressure.

[0131] It should be noted that the warm-up phase ends when the hot air enters the coal mill for longer than the preset warm-up time. At this point, the exhaust draft fan damper actuator 8 is controlled to adjust its opening to the initial opening (usually no more than 5%), and the exhaust draft fan 10 is automatically activated, directing the exhaust gas from the hot blast furnace into the drying furnace 1, where it mixes with the high-temperature post-combustion gases to form a high-temperature inert gas. This rapidly reduces the oxygen content in the high-temperature flue gas output from the drying furnace 1. Once the oxygen content in the high-temperature flue gas output from the drying furnace 1 falls within the production range, the coal drying phase begins.

[0132] In one embodiment of the present invention, the acquired first pressure is compared with a threshold value of the furnace pressure of the drying furnace, and the opening of the exhaust gas induced draft fan damper actuator 8 is adjusted according to the comparison result.

[0133] It should be noted that the drying furnace hearth pressure threshold includes the drying furnace hearth pressure upper limit P H And the lower limit of the drying furnace pressure P L .

[0134] When P Act >P H When the exhaust induced draft fan damper actuator 8 is opened, the exhaust induced draft fan damper actuator 8 opening adjustment gradient is reduced to reduce the drying furnace hearth pressure, which can be expressed by the following formula:

[0135] V 3Set =V 3Init -V 3△ ;

[0136] When P Act <P L When the exhaust gas induced draft fan damper actuator 8 increases the opening of the exhaust gas induced draft fan damper actuator 8, the opening adjustment gradient is increased to increase the drying furnace hearth pressure, which can be expressed by the following formula:

[0137] V 3Set =V 3Init +V 3△ ;

[0138] When P L ≤P Act ≤P H When the exhaust fan damper actuator 8 opens, the opening is not adjusted.

[0139] Among them, P Act Indicates the first pressure; V 3Set Indicates the opening of the exhaust gas induced draft fan damper actuator 8 30 seconds after entering the coal baking stage; V 3InitIndicates the initial opening of the exhaust draft fan damper actuator 8; V 3△ Indicates the opening adjustment gradient of the exhaust draft fan damper actuator 8.

[0140] In one embodiment of the present invention, step S260, controlling the second temperature within the preset value range of the pulverizer inlet temperature and the third temperature within the preset value range of the pulverizer outlet temperature according to the current combustion program, may include steps S261 to S262.

[0141] It should be noted that the second temperature and the third temperature are obtained by using the temperature sensor after the warm grinding stage, that is, when the high-temperature flue gas output by the drying furnace 1 enters the coal mill.

[0142] For example, the preset value range of the coal mill inlet temperature is 270°C to 285°C, and the preset value range of the coal mill outlet temperature is 80°C to 90°C.

[0143] Step S261, when the current combustion model is the first combustion program, the blast furnace gas flow entering the drying furnace 1 is controlled by the first controller to control the second temperature within the preset value range of the pulverizer inlet temperature and the third temperature within the preset value range of the pulverizer outlet temperature.

[0144] Specifically, when the preset value range of the coal mill inlet temperature is less than 270°C, the first controller controls the blast furnace gas flow regulating valve 3 to increase the opening of the blast furnace gas flow regulating gradient F by two. 2△ The valve opening corresponding to the valve flow characteristic curve is used to increase the blast furnace gas flow entering the drying furnace 1, so that the pulverizer inlet temperature rises; when the pulverizer inlet temperature preset value range is greater than 285 ° C, the first controller controls the blast furnace gas flow regulating valve 3 to reduce the opening of two blast furnace gas flow regulating gradients F 2△ The valve opening corresponding to the valve flow characteristic curve is used to reduce the blast furnace gas flow entering the drying furnace 1, so that the pulverizer inlet temperature drops; when the pulverizer inlet temperature preset value range is greater than 290 ° C, the first controller controls the blast furnace gas flow regulating valve 3 to reduce the opening of the blast furnace gas flow regulating gradient F 2△ The corresponding valve opening in the valve flow characteristic curve reduces the blast furnace gas flow entering the drying furnace 1, so that the pulverizer inlet temperature drops.

[0145] When the preset range of the coal mill outlet temperature is less than 80℃ and the coal mill inlet temperature is within the range of 270℃~285℃, the first controller controls the blast furnace gas flow regulating valve 3 to increase the opening of the blast furnace gas flow regulating gradient F 2△The valve opening corresponding to the valve flow characteristic curve is used to increase the blast furnace gas flow entering the drying furnace 1, so that the mill outlet temperature rises; when the mill inlet temperature preset value range is greater than 90 ° C, and the mill inlet temperature is within the range of 270 ° C to 285 ° C, the first controller controls the blast furnace gas flow regulating valve 3 to reduce the opening of the blast furnace gas flow regulating gradient F 2△ The corresponding valve opening in the valve flow characteristic curve reduces the blast furnace gas flow entering the drying furnace 1, so that the pulverizer inlet temperature drops.

[0146] Step S262, when the current combustion model is the second combustion program, the blast furnace gas flow entering the drying furnace 1 is controlled by the second controller to control the second temperature within the preset value range of the pulverizer inlet temperature and the third temperature within the preset value range of the pulverizer outlet temperature.

[0147] Specifically, when the preset value range of the coal mill inlet temperature is less than 270°C, the second controller controls the opening of the blast furnace gas flow regulating valve 3 to increase the valve position adjustment gradient V of the two blast furnace gas flow regulating valves 3. 2△ , in order to increase the blast furnace gas flow entering the drying furnace 1, so that the mill inlet temperature rises; when the mill inlet temperature preset value range is greater than 285 ℃, the second controller controls the opening of the blast furnace gas flow regulating valve 3 to reduce the valve position adjustment gradient V of the two blast furnace gas flow regulating valves 3 2△ , in order to reduce the blast furnace gas flow entering the drying furnace 1, so that the mill inlet temperature drops; when the mill inlet temperature preset value range is greater than 290 ℃, the second controller controls the opening of the blast furnace gas flow regulating valve 3 to reduce the valve position adjustment gradient V of the blast furnace gas flow regulating valve 3 by five 2△ , in order to reduce the blast furnace gas flow entering the drying furnace 1, so that the pulverizer inlet temperature drops.

[0148] When the preset range of the coal mill outlet temperature is less than 80°C and the coal mill inlet temperature is within the range of 270°C to 285°C, the second controller controls the opening of the blast furnace gas flow regulating valve 3 to increase the valve position adjustment gradient V of the blast furnace gas flow regulating valve 3. 2△ , in order to increase the blast furnace gas flow entering the drying furnace 1, so that the mill outlet temperature rises; when the mill inlet temperature preset value range is greater than 90 ℃, and the mill inlet temperature is within the range of 270 ℃ to 285 ℃, the second controller controls the opening of the blast furnace gas flow regulating valve 3 to reduce the valve position adjustment gradient V of the blast furnace gas flow regulating valve 3. 2△ , in order to reduce the blast furnace gas flow entering the drying furnace 1, so that the pulverizer inlet temperature drops.

[0149] For example, the coal mill inlet temperature may be adjusted once every 30 seconds, and the coal mill outlet temperature may be adjusted once every 60 seconds. Alternatively, the time intervals for adjustment may be selected according to actual needs.

[0150] In an exemplary embodiment, the automatic control method for a drying furnace in a blast furnace coal injection system may further include steps S310 to S340.

[0151] Step S310: The pulverizing capacity is divided into N pulverizing levels according to the pulverizing capacity of the equipment, and each pulverizing level is provided with a corresponding set flow rate of blast furnace gas.

[0152] For example, the milling amount is divided into 10 milling levels according to the milling capacity of the equipment, as shown in Table 1.

[0153] Table 1

[0154]

[0155] Step S320: obtaining a first powder production amount.

[0156] Specifically, the first pulverizing amount is the real-time pulverizing amount of the blast furnace pulverizing system.

[0157] It should be noted that after entering the coal baking stage, the coal injection system starts to unload coal, and at this time the first pulverizing amount can be obtained through the weighing equipment.

[0158] Step S330: determining the milling grade according to the first milling amount.

[0159] It should be noted that the first pulverizing amount is the real-time pulverizing amount of the blast furnace pulverizing system. The real-time pulverizing amount of the blast furnace pulverizing system is compared with the pulverizing amounts corresponding to each pulverizing grade to determine the pulverizing grade of the first pulverizing amount.

[0160] For example, if the first powder production capacity is 28t / h and the first flow rate is 2200m 3 / h. The pulverizing grade is determined to be W3 according to the first pulverizing amount. The blast furnace gas flow rate corresponding to the pulverizing grade W3 is set to 2200m 3 / h.

[0161] Step S340: setting the blast furnace gas flow rate adjusted by the first controller as the blast furnace gas flow rate setting flow rate of the pulverizing grade, and serving as the initial blast furnace gas target flow rate for the next pulverizing step.

[0162] Specifically, to ensure that the second temperature and the third temperature are within the preset ranges of the coal mill inlet temperature and the coal mill outlet temperature, respectively, the blast furnace gas flow rate entering the drying furnace 1 is controlled by the first controller, and the adjusted blast furnace gas flow rate is set as the set blast furnace gas flow rate for the pulverizing grade. The next time the blast furnace coal injection system enters the coal drying phase, the adjusted set blast furnace gas flow rate is tracked as the blast furnace gas target flow rate to regulate the first flow rate.

[0163] To sum up, the scheme of this embodiment completes the ignition and combustion of the drying furnace through the ignition program and the combustion program, and controls the furnace pressure of the drying furnace by controlling the opening of the exhaust gas draft fan damper regulating valve, which can quickly and accurately adjust the furnace temperature and furnace pressure of the drying furnace, avoid system fluctuations caused by manual operation, and realize the automation of blast furnace gas combustion; and by obtaining the first pulverizing amount and determining the blast furnace gas set flow rate, data is provided for subsequent pulverizing, thereby improving the reliability of coal injection, and thereby improving the quality of coal powder produced by the pulverizing system.

[0164] See also Figure 4 , Figure 4 4 is a block diagram of an automatic control device for a drying furnace of a blast furnace coal injection system according to an exemplary embodiment of the present invention. The exemplary blast furnace gas combustion control device includes: a detection module 410 , an acquisition module 420 , a regulation module 430 and a recording module 440 .

[0165] Detection module 410, used to detect the presence of a coke oven gas pipeline;

[0166] The ignition module 420 determines the ignition procedure according to the detection results of the coke oven gas pipeline;

[0167] An acquisition module 430 is configured to acquire a first flow rate, a first opening degree, a first temperature, a first pressure, and a first powder production amount;

[0168] The combustion module 440 determines a combustion program according to a correspondence between the first flow rate and the first opening degree;

[0169] The control module 450 is used to control the first temperature within a temperature threshold range, control the opening of the exhaust draft fan damper actuator 8 so that the first pressure is within a drying furnace furnace pressure threshold range, control the second temperature within a coal mill inlet temperature preset value range, and control the third temperature within a coal mill outlet temperature preset value range.

[0170] It should be noted that the blast furnace gas combustion control device provided in the above embodiment and the automatic control method for the drying furnace of the blast furnace coal injection system provided in the above embodiment are based on the same concept. The specific procedures for executing the operations of each module and unit have been described in detail in the method embodiment and will not be repeated here. In actual application, the blast furnace gas combustion control device provided in the above embodiment can allocate the above functions to different functional modules as needed, that is, divide the internal structure of the device into different functional modules to complete all or part of the functions described above, and this is not limited here.

[0171] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. Each box in the flowchart or block diagram can represent a module, program segment, or part of the code, and the above-mentioned module, program segment, or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the boxes can also occur in an order different from that marked in the accompanying drawings. For example, two boxes shown in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or can be implemented using a combination of dedicated hardware and computer instructions.

[0172] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, any equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

[0173] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for automatically controlling a drying furnace in a blast furnace coal injection system, characterized in that: The method comprises: Detection of coke oven gas pipelines; determining an ignition procedure according to the detection result of the coke oven gas pipeline; Obtain a first flow rate, a first opening, a first temperature, a second temperature, a third temperature, and a first pressure, wherein the first flow rate is the real-time flow rate of blast furnace gas, the first opening is the real-time opening of the blast furnace gas flow control valve, the first temperature is the real-time temperature of the drying furnace hearth, the second temperature is the real-time temperature of the coal mill inlet, the third temperature is the real-time temperature of the coal mill outlet, and the first pressure is the real-time pressure of the drying furnace hearth; determining a combustion program according to a correspondence between the first opening degree and the first flow rate so that the first temperature is within a temperature threshold range; The combustion program includes a first combustion program; When the corresponding relationship conforms to the valve flow characteristic curve, selecting the first combustion program; adjusting the opening of a blast furnace gas flow regulating valve by a first controller to control the flow of the blast furnace gas entering the drying furnace so that the first temperature is within the temperature threshold range, wherein the first controller is a PID regulation controller; The combustion program includes a second combustion program; When the corresponding relationship does not conform to the valve flow characteristic curve, selecting the second combustion program; adjusting the opening of the blast furnace gas flow regulating valve by a second controller to control the flow of blast furnace gas entering the drying furnace so that the first temperature is within the temperature threshold range, the second controller being a blast furnace gas flow regulating valve opening controller; Determining the opening of the exhaust gas induced draft fan damper actuator according to the first pressure so that the first pressure is within a threshold range of the drying furnace hearth pressure; According to the current combustion program, the second temperature is controlled within a preset value range of the coal mill inlet temperature, and the third temperature is controlled within a preset value range of the coal mill outlet temperature.

2. The automatic control method for a drying furnace of a blast furnace coal injection system according to claim 1, characterized in that: The step of determining an ignition procedure based on the detection result of the coke oven gas pipeline includes: The ignition program includes a first ignition program and a second ignition program; When no coke oven gas pipeline is detected, the first ignition program is selected and blast furnace gas is input to complete ignition; When the presence of a coke oven gas pipeline is detected, the second ignition procedure is selected and coke oven gas is input to complete ignition.

3. The automatic control method for a drying furnace in a blast furnace coal injection system according to claim 1, characterized in that: The step of determining a combustion program according to the corresponding relationship between the first opening and the first flow rate so that the first temperature is within a temperature threshold range includes: When in the heat preservation stage, the temperature thresholds include the heat preservation temperature of the drying furnace and the upper limit of the heat dissipation temperature of the drying furnace; When in the warm grinding stage, the temperature thresholds include an upper temperature limit of the drying furnace warm grinding and a lower temperature limit of the drying furnace warm grinding.

4. The automatic control method for a drying furnace in a blast furnace coal injection system according to claim 1, characterized in that: The step of controlling the second temperature within a preset value range of the coal mill inlet temperature and the step of controlling the third temperature within a preset value range of the coal mill outlet temperature according to the current combustion program includes: When the current combustion program is the first combustion program, the flow rate of the blast furnace gas entering the drying furnace is controlled by the first controller to control the second temperature within a preset value range of a coal mill inlet temperature, and the third temperature within a preset value range of a coal mill outlet temperature; When the current combustion program is the second combustion program, the blast furnace gas flow entering the drying furnace is controlled by the second controller to control the second temperature within the preset value range of the pulverizer inlet temperature and the third temperature within the preset value range of the pulverizer outlet temperature.

5. The automatic control method for a drying furnace in a blast furnace coal injection system according to claim 4, characterized in that: When the current combustion program is the first combustion program, after controlling the flow rate of the blast furnace gas entering the drying furnace by the first controller to control the second temperature within a preset range of a coal mill inlet temperature and the third temperature within a preset range of a coal mill outlet temperature, the method further includes: The pulverizing capacity is divided into N pulverizing levels according to the pulverizing capacity of the equipment, and each pulverizing level is provided with a corresponding blast furnace gas set flow rate; Obtaining a first pulverizing amount, where the first pulverizing amount is a real-time pulverizing amount of a blast furnace pulverizing system; determining the milling grade according to the first milling amount; The blast furnace gas flow rate adjusted by the first controller is set as the blast furnace gas flow rate setting flow rate of the pulverizing grade, and is used as the initial blast furnace gas target flow rate for the next pulverizing grade.

6. The automatic control method for a drying furnace in a blast furnace coal injection system according to claim 1, characterized in that: After determining the ignition procedure according to the detection result of the coke oven gas pipeline, the method further includes: Check the display light of the flame detector; If it is detected that the display light is on, the ignition is successful and the combustion procedure is implemented; If the display light is not detected to be on, the ignition fails, and the ignition procedure is repeated until the display light is detected to be on.

7. An automatic control device for a drying furnace of a blast furnace coal injection system, used to implement the automatic control method for a drying furnace of a blast furnace coal injection system according to any one of claims 1 to 6, characterized in that: The device comprises: Detection module, used to detect the presence of coke oven gas pipelines; an ignition module, which determines an ignition procedure according to the detection result of the coke oven gas pipeline; an acquisition module, configured to acquire a first flow rate, a first opening degree, a first temperature, a second temperature, a third temperature, and a first pressure; a combustion module, determining a combustion program according to a correspondence between the first flow rate and the first opening; A control module is used to control the first temperature to be within a temperature threshold range, control the opening of the exhaust draft fan damper actuator so that the first pressure is within a drying furnace furnace pressure threshold range, control the second temperature to be within a preset value range of the pulverizer inlet temperature, and control the third temperature to be within a preset value range of the pulverizer outlet temperature.

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