Carbon cycle blast furnace equipped with blast furnace gas safety control system and control method thereof

Abstract

The present invention provides a carbon cycle blast furnace equipped with a blast furnace gas safety control system and a control method thereof, belonging to the field of steel smelting technology. The blast furnace comprises a blast furnace body, a gas heating furnace, and a central controller; the gas heating furnace comprises a flame burner and a heating furnace body; a first pipeline, a second pipeline, and a third pipeline are provided between the blast furnace body and the gas heating furnace; the top of the blast furnace body is connected to the flame burner via the first pipeline, the top of the blast furnace body is connected to the heating furnace body via the second pipeline, and the heating furnace body is connected to the blast furnace body via the third pipeline. The present invention can monitor and adjust the combustion conditions of the flame burner and the flow and pressure on each pipeline, thereby achieving safe control of the carbon cycle blast furnace, quickly and accurately adjusting the flow and pressure of each gas pipeline and air pipeline, avoiding accidents such as gas leakage, tempering, and explosion, improving the safety performance of the carbon cycle blast furnace, and ensuring safe production operation.

Description

Technical Field

[0001] The present invention relates to the technical field of steel smelting equipment, and in particular to a carbon cycle blast furnace provided with a blast furnace gas safety control system and a control method thereof. Background Art

[0002] In the blast furnace process, about 34% of carbon is emitted in the form of blast furnace gas. This part of gas is an unused carbon resource for steelmaking. As a by-product of the ironmaking process, blast furnace gas mainly consists of CO, CO2, N2, H2 and CH4. Among them, the combustible component CO accounts for about 25%, CO2 and N2 account for 15% and 55% respectively, and the content of H2 and CH4 is very small. The calorific value is only 3500KJ / m 3 Currently, blast furnace gas is mostly used for heating hot blast furnaces, but due to various factors, the temperature of blast furnace gas must be much higher than the ignition point to ensure combustion stability. The carbon circulation blast furnace is a low-carbon ironmaking technology that uses top gas circulation reduction. It can maximize the utilization of chemical energy in blast furnace gas, reduce the proportion of blast furnace reducing agents and the energy consumption of the ironmaking production system. Blast furnace gas, converter gas and coke oven gas are all flammable and explosive gases, and decarbonization of gas will increase the explosiveness of the gas. The explosion limit of blast furnace gas is 40.0%-70.0%. Therefore, the carbon circulation blast furnace has certain safety risks in the gas combustion, heating and injection processes. Summary of the Invention

[0003] In view of the shortcomings of the prior art described above, the object of the present invention is to provide a carbon cycle blast furnace equipped with a blast furnace gas safety control system and a control method thereof, so as to solve the problem that the carbon cycle blast furnace in the prior art has certain safety risks in the gas combustion, heating and injection processes.

[0004] To achieve the above-mentioned and other related purposes, the present invention provides a carbon cycle blast furnace equipped with a blast furnace gas safety control system, comprising a blast furnace body, a gas heating furnace and a central controller;

[0005] The gas heating furnace includes a flame burner and a heating furnace body. A first pipeline, a second pipeline, and a third pipeline are provided between the blast furnace body and the gas heating furnace. The top of the blast furnace body is connected to the flame burner via the first pipeline, the top of the blast furnace body is connected to the heating furnace body via the second pipeline, and the heating furnace body is connected to the blast furnace body via the third pipeline.

[0006] The top gas of the blast furnace body enters the flame burner through the first pipeline for combustion, and heats the heating furnace body. When the heating furnace body is heated to meet a preset temperature threshold, the top gas of the blast furnace body enters the heating furnace body through the second pipeline. The heating furnace body heats the top gas. The heated top gas in the heating furnace body enters the blast furnace body through the third pipeline. The flame burner is connected to a combustion-supporting pipeline, and the combustion-supporting gas enters the flame burner through the combustion-supporting pipeline.

[0007] The gas heating furnace is provided with a flame monitoring device and a furnace pressure monitoring device, and the flame monitoring device and the furnace pressure monitoring device are respectively connected to the central control unit by signal;

[0008] The heating furnace body is provided with a temperature monitoring device and a gas composition monitoring device, and the temperature monitoring device and the gas composition monitoring device are respectively connected to the central controller by signal;

[0009] The first pipeline, the second pipeline and the combustion-supporting pipeline are all provided with a pressure monitoring device, a pressure regulating device, and a flow monitoring and regulating device. The third pipeline is provided with a pressure monitoring device, a pressure regulating device and a flow monitoring device. The pressure monitoring device, the pressure regulating device, the flow monitoring device, the temperature monitoring device, the gas composition monitoring device and the flow monitoring and regulating device are respectively connected to the central controller signal.

[0010] Optionally, there are at least two gas heating furnaces, the top of the blast furnace body is connected to each of the flame burners through the first pipeline, the top of the blast furnace body is connected to each of the heating furnace bodies through the second pipeline, and each of the heating furnace bodies is connected to the blast furnace body through the third pipeline.

[0011] Optionally, there are three gas heating furnaces.

[0012] Optionally, a decarbonization device is provided on the second pipeline, and the decarbonization device is used to remove carbon dioxide from the top gas.

[0013] Optionally, the second pipeline is also connected to a surplus gas pipeline, and the gas in the surplus gas pipeline enters the heating furnace body through the second pipeline.

[0014] The present invention also provides a safety control method for a carbon cycle blast furnace, which uses the carbon cycle blast furnace as described in any one of the above items, comprising the following steps:

[0015] The flame monitoring device monitors the combustion condition of the flame burner.

[0016] If the flame goes out, the current gas composition in the furnace of the heating furnace body is monitored by gas composition, and the safety threshold is determined according to the current gas composition in the furnace of the heating furnace body.

[0017] Close the first pipeline and increase the flow rate of the combustion-supporting pipeline until the gas composition in the furnace of the heating furnace body is lower than the safety threshold and then re-ignite.

[0018] Optionally, the pressure in the first pipeline is obtained by a pressure monitoring device provided on the first pipeline, and the pressure in the furnace of the heating furnace body is obtained by the furnace pressure monitoring device, and the difference between the pressure in the first pipeline and the pressure in the furnace of the heating furnace body is the pressure difference value;

[0019] The pressure difference value is compared with a preset pressure difference threshold value. If the pressure difference value is lower than the pressure difference threshold value, the pressure of the top gas in the first pipeline is increased and / or the pressure of the combustion-supporting gas in the combustion-supporting pipeline is reduced.

[0020] Optionally, the post-combustion oxygen concentration of the flame burner is monitored by an online gas composition monitoring device. If the post-combustion oxygen concentration exceeds a preset oxygen concentration threshold, the flow in the combustion-supporting pipeline and the flow in the first pipeline are adjusted until the post-combustion oxygen concentration is lower than the oxygen concentration threshold.

[0021] Optionally, the temperature of the heating furnace body is obtained by a temperature monitoring device.

[0022] If the temperature of the heating furnace body is lower than or equal to the temperature threshold, the first pipeline is opened and the second pipeline is closed to heat the heating furnace body through the flame burner;

[0023] If the temperature of the heating furnace body is higher than a preset temperature threshold, the first pipeline is closed and the second pipeline is opened to heat the coal gas in the heating furnace body through the heating furnace body.

[0024] Optionally, the pressure value in the third pipeline is obtained by a pressure monitoring device arranged on the third pipeline. If the pressure value is lower than a preset pressure threshold, it is necessary to pressurize the third pipeline through a pressure regulating device arranged on the third pipeline until the pressure value meets the pressure threshold.

[0025] As described above, the carbon cycle blast furnace provided with a blast furnace gas safety control system and the control method thereof of the present invention have the following beneficial effects: by arranging a flame monitoring device, a furnace pressure monitoring device, a temperature monitoring device, a gas composition monitoring device, a pressure monitoring device, a pressure regulating device, a flow monitoring device, a flow monitoring and regulating device and a central controller, the combustion conditions of the flame burner and the flow and pressure on each pipeline can be monitored and regulated, thereby realizing safe control of the carbon cycle blast furnace, quickly and accurately adjusting the flow and pressure of each gas pipeline and air pipeline, avoiding accidents such as gas leakage, tempering, explosion, etc., increasing the safety performance of the carbon cycle blast furnace, and ensuring safe production operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Shown is a structural schematic diagram of a carbon cycle blast furnace equipped with a blast furnace gas safety control system in an embodiment of the present invention.

[0027] Figure 2 Display as Figure 1 Enlarged schematic diagram of the medium-pressure gas heating furnace.

[0028] Figure 3 Display as Figure 2 Schematic diagram of the structure of the material guide channel.

[0029] Figure 4 Shown is a safety control logic block diagram of a carbon cycle blast furnace in an embodiment of the present invention.

[0030] Figure 5 Shown is a logic block diagram of top gas circulation control of a carbon circulation blast furnace in an embodiment of the present invention.

[0031] Description of reference numerals:

[0032] Blast furnace body 1, hot air blowing pipe 2, furnace top 3, decarbonization device 4, gas heating furnace 5, central controller 6, flow monitoring and adjustment device 7, pressure adjustment device 8, pressure monitoring device 9, first pipeline 10, second pipeline 20, third pipeline 30, gas spray gun 31, combustion-supporting pipeline 40, surplus gas pipeline 50, flame burner 51, heating furnace body 52, high-temperature exhaust gas pipeline 60, flame monitoring device 61, furnace pressure monitoring device 62, gas composition monitoring device 63, temperature monitoring device 64, flow monitoring device 65. DETAILED DESCRIPTION

[0033] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] It should be noted that the diagrams provided in the present embodiment are only schematic illustrations of the basic concept of the present invention. The diagrams only show the components related to the present invention and are not drawn according to the number, shape and size of the components during actual implementation. The type, quantity and ratio of each component during actual implementation can be changed at will, and the component layout type may also be more complex. The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read. They are not used to limit the limiting conditions for the implementation of the present invention. Therefore, they have no technical significance. Any modification of the structure, change of the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the efficacy and purpose of the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description and are not used to limit the scope of the implementation of the present invention. Changes or adjustments in their relative relationships should also be considered as the scope of the implementation of the present invention without substantially changing the technical content.

[0035] See also Figure 1 and Figure 2 This embodiment provides a carbon cycle blast furnace equipped with a blast furnace gas safety control system, comprising a blast furnace body 1, a gas heating furnace 5 and a central controller 6;

[0036] The gas heating furnace 5 includes a flame burner 51 and a heating furnace body 52. ​​A first pipeline 10, a second pipeline 20, and a third pipeline 30 are provided between the blast furnace body 1 and the gas heating furnace 5. The furnace top 3 of the blast furnace body 1 is connected to the flame burner 51 through the first pipeline 10, and the furnace top 3 of the blast furnace body 1 is connected to the heating furnace body 52 through the second pipeline 20. The heating furnace body 52 is connected to the blast furnace body 1 through the third pipeline 30.

[0037] The top gas of the blast furnace body 1 enters the flame burner 51 through the first pipeline 10 for combustion, and heats the heating furnace body 52. ​​When the heating furnace body 52 is heated to a preset temperature threshold, the top gas of the blast furnace body 1 enters the heating furnace body 52 through the second pipeline 20. The heating furnace body 52 heats the top gas. The heated top gas in the heating furnace body 52 enters the blast furnace body 1 through the third pipeline 30. The flame burner 51 is connected to the combustion-supporting pipeline 40, and the combustion-supporting gas enters the flame burner 51 through the combustion-supporting pipeline 40.

[0038] The gas heating furnace 5 is provided with a flame monitoring device 61 and a furnace pressure monitoring device 62, which are respectively connected to the central control unit for signal transmission;

[0039] The heating furnace body 52 is provided with a temperature monitoring device 64 and a gas composition monitoring device 63, which are respectively connected to the central controller 6 for signal transmission;

[0040] The first pipeline 10, the second pipeline 20 and the combustion-supporting pipeline 40 are all provided with a pressure monitoring device 9, a pressure regulating device 8, and a flow monitoring and regulating device 7. The third pipeline 30 is provided with a pressure monitoring device 9, a pressure regulating device 8 and a flow monitoring device 65. The pressure monitoring device 9, the pressure regulating device 8, the flow monitoring device 65, the temperature monitoring device 64, the gas composition monitoring device 63 and the flow monitoring and regulating device 7 are respectively connected to the central controller 6 for signals.

[0041] The flame monitoring device 61 is installed near the flame burner 51 of the gas heating furnace 5 and is used to monitor whether the flame burner 51 of the gas heating furnace 5 is burning normally. The furnace pressure monitoring device 62, gas composition monitoring device 63 and temperature monitoring device 64 are installed on the heating furnace body 52 of the gas heating furnace 5 and are used to monitor whether the gas composition, pressure and temperature in the furnace of the heating furnace body 52 are normal.

[0042] In this embodiment, by setting up a flame monitoring device 61, a furnace pressure monitoring device 62, a temperature monitoring device 64, a gas composition monitoring device 63, a pressure monitoring device 9, a pressure regulating device 8, a flow monitoring device 65, a flow monitoring and regulating device 7 and a central controller 6, the combustion condition of the flame burner 51 and the flow and pressure on each pipeline can be monitored and adjusted, thereby achieving safe control of the carbon cycle blast furnace, quickly and accurately adjusting the flow and pressure of each gas pipeline and air pipeline, avoiding accidents such as gas leakage, tempering, explosion, etc., increasing the safety performance of the carbon cycle blast furnace, and ensuring safe production operation.

[0043] In this embodiment, there are at least two gas heating furnaces 5. The roof 3 of the blast furnace body 1 is connected to each flame burner 51 via a first pipeline 10. The roof 3 of the blast furnace body 1 is connected to each heating furnace body 52 via a second pipeline 20. Each heating furnace body 52 is connected to the blast furnace body 1 via a third pipeline 30. The two gas heating furnaces 5 can operate alternately to achieve continuous heating of the top gas, ensuring a continuous supply of top gas to the blast furnace body 1.

[0044] Specifically, in this embodiment, there are three gas heating furnaces 5. Two of the gas heating furnaces 5 are in operation, and the other is in standby mode. When one of the operating gas heating furnaces 5 stops working due to a fault or other reason, the standby gas heating furnace 5 can be activated to ensure continuous heating of the top gas of multiple furnaces.

[0045] Specifically, in this embodiment, a carbon removal device 4 is provided on the second pipeline 20 to remove carbon dioxide from the top gas. In some embodiments, the second pipeline 20 is also provided with dust removal, power generation, desulfurization, and dehydration devices to purify the blast furnace gas before decarbonization.

[0046] In this embodiment, the second pipeline 20 is also connected to the surplus gas pipeline 50. The gas in the surplus gas pipeline 50 is mixed with the top gas in the gas mixing device and then enters the heating furnace body 52 through the second pipeline 20. The gas in the surplus gas pipeline 50 can be decarbonized by the decarbonization device 4 on the second pipeline 20, or it can be mixed with the top gas in the second pipeline 20 after decarbonization.

[0047] Figure 1 The dashed lines represent signal connections. The flame monitoring device 61, furnace pressure monitoring device 62, temperature monitoring device 64, gas composition monitoring device 63, pressure monitoring device 9, pressure regulating device 8, flow monitoring device 65, and flow monitoring and regulating device 7 each transmit collected data in the form of signals to the central controller 6. Based on the received data and parameters such as the operating conditions of the blast furnace 1, the central controller 6 generates control instructions. The central controller 6 transmits these control instructions in the form of signals to the flow monitoring and regulating devices 7 and pressure regulating devices 8. The flow regulating devices and pressure regulating devices 8 adjust the pressure and flow according to the control instructions from the central controller 6, thereby achieving safe regulation of the carbon cycle blast furnace production process.

[0048] For example, the central controller 6 can adjust the flow rate and pressure of the gas in the first pipeline 10 entering the flame burner 51 through the flow rate monitoring and regulating device 7 and the pressure regulating device 8 on the first pipeline 10 based on the combustion conditions of the gas heating furnace 5 obtained by the temperature monitoring device 64, and the flow rate and pressure of the gas in the first pipeline 10 obtained by the flow rate monitoring and regulating device 7 and the pressure monitoring device 9 on the first pipeline 10.

[0049] The central controller 6 can also adjust the flow rate and pressure of the gas in the second pipeline 20 entering the heating furnace body 52 through the flow rate monitoring and regulating device 7 and the pressure regulating device 8 on the second pipeline 20 based on the combustion conditions of the gas heating furnace 5 obtained by the temperature monitoring device 64, and the flow rate and pressure of the gas in the second pipeline 20 obtained by the flow rate monitoring and regulating device 7 and the pressure monitoring device 9 on the second pipeline 20.

[0050] A flow regulating device may be provided on the surplus gas pipeline 50 to adjust the flow of gas from the surplus gas pipeline 50 into the first pipeline 10. The central controller 6 may be signal-connected to the flow regulating device on the surplus gas pipeline 50 and the blast furnace body 1. Based on the combustion conditions of the gas heating furnace 5 as determined by the temperature monitoring device 64, the flow and pressure of the gas in the second pipeline 20 as determined by the flow monitoring and regulating device 7 and the pressure monitoring device 9 on the second pipeline 20, and the requirements of the blast furnace body 1, the flow and pressure of the gas in the second pipeline 20 into the heating furnace body 52 are regulated by the flow monitoring and regulating device 7 and the pressure regulating device 8 on the second pipeline 20, as well as the flow regulating device on the surplus gas pipeline 50.

[0051] The central controller 6 can adjust the flow rate and pressure of the gas in the second pipeline 20 entering the heating furnace body 52 through the flow rate monitoring and regulating device 7 and the pressure regulating device 8 on the second pipeline 20 based on the combustion conditions of the gas heating furnace 5 obtained by the temperature monitoring device 64, and the flow rate and pressure of the gas in the second pipeline 20 obtained by the flow rate monitoring and regulating device 7 and the pressure monitoring device 9 on the second pipeline 20.

[0052] The flame monitoring device 61 can monitor whether the flame burner 51 is burning normally and feed the data back to the central controller 6. The central controller 6 can adjust the flow rate and pressure of the gas flowing into the flame burner 51 in the first pipeline 10, as well as the flow rate and pressure of the combustion-supporting gas flowing into the flame burner 51 in the combustion-supporting pipeline 40, through the flow rate monitoring and regulating device 7 and the pressure regulating device 8 on the first pipeline 10, as well as the flow rate monitoring and regulating device 7 and the pressure regulating device 8 on the combustion-supporting pipeline 40, based on the combustion condition of the flame burner 51 obtained by the flame monitoring device 61, the flow rate and pressure of the coal gas in the first pipeline 10 obtained by the flow rate monitoring and regulating device 7 and the pressure monitoring device 9 on the first pipeline 10, and the flow rate and pressure of the combustion-supporting gas in the combustion-supporting pipeline 40 obtained by the flow rate monitoring and regulating device 7 and the pressure regulating device 9 on the combustion-supporting pipeline 40.

[0053] In this embodiment, the temperature monitoring device 64 is a thermocouple, and the furnace pressure monitoring device 62, the gas composition monitoring device 63 and the temperature monitoring device 64 can monitor whether the gas composition, pressure and temperature in the furnace of the heating furnace body 52 are normal, and feed back the monitoring data to the central controller 6.

[0054] The central controller 6 can obtain monitoring data based on the furnace pressure monitoring device 62, the gas composition monitoring device 63 and the temperature monitoring device 64, the flow rate and pressure of the coal gas in the first pipeline 10 obtained by the flow monitoring and regulating device 7 and the pressure monitoring device 9 on the first pipeline 10, and the flow rate and pressure of the combustion-supporting gas in the combustion-supporting pipeline 40 obtained by the flow monitoring and regulating device 7 and the pressure monitoring device 9 on the combustion-supporting pipeline 40, and adjust the flow rate and pressure of the coal gas in the first pipeline 10 entering the flame burner 51 and the flow rate and pressure of the combustion-supporting gas in the combustion-supporting pipeline 40 through the flow monitoring and regulating device 7 and the pressure regulating device 8 on the first pipeline 10 and the flow monitoring and regulating device 7 and the pressure regulating device 8 on the combustion-supporting pipeline 40.

[0055] A flow regulating device can be set on the hot air blowing pipeline of the blast furnace body 1, and the central controller 6 can be connected to the signal of the flow regulating device on the hot air blowing pipeline. The pressure monitoring device 9 and the flow monitoring device 65 on the third pipeline 30 can monitor the pressure and flow of the decarbonized top gas input to the blast furnace body 1, and feed back the monitoring data to the central controller 6.

[0056] The central controller 6 can obtain monitoring data based on the furnace pressure monitoring device 62, the gas composition monitoring device 63 and the temperature monitoring device 64, and the flow and pressure of the coal gas in the third pipeline 30 monitored by the pressure monitoring device 9 and the flow monitoring device 65 on the third pipeline 30. Through the flow monitoring device 65 and the pressure regulating device 8 on the third pipeline 30, the pressure of the coal gas entering the blast furnace body 1 in the third pipeline 30 is adjusted, and the hot air flow of the hot air injection pipeline is adjusted through the flow regulating device on the hot air injection pipeline to ensure that the air intake of the blast furnace tuyere remains unchanged.

[0057] See also Figure 3 This embodiment also provides a safety control method for a carbon cycle blast furnace, which uses the carbon cycle blast furnace as described above and includes the following steps:

[0058] S10: The combustion condition of the flame burner 51 is monitored by the flame monitoring device 61 .

[0059] S11: If the flame is extinguished, the gas composition monitoring device 63 monitors the current gas composition in the furnace of the heating furnace body 52 and determines the safety threshold value according to the current gas composition in the furnace of the heating furnace body 52.

[0060] S12: Close the first pipeline 10 and increase the flow rate of the combustion-supporting pipeline until the gas composition in the furnace of the flame burner 51 is lower than the safety threshold and then re-ignite.

[0061] Specifically, the flame monitoring device 61 can monitor whether the flame burner 51 is burning normally. If the flame is extinguished, the first pipeline 10 is quickly closed and the air flow of the combustion-supporting pipeline 40 is increased to purge the gas heating furnace 5. The gas composition monitoring device 63 monitors the gas composition in the furnace of the gas heating furnace 5, that is, the heating furnace body 52 in real time. For example, the gas composition can be shown in the following table:

[0062]

[0063] Using Le Chatelier's principle, and referring to Figure 4 The gas explosion limit diagram shown in the figure shows that the lower explosion limit (LEL) for the current gas composition is 32.98%. When the air in the combustion-supporting pipeline 40 is purged to a gas concentration in the gas heating furnace 5 below a safety threshold (e.g., 25% LEL), namely, 8.25%, ignition of the gas heating furnace 5 can be resumed. The gas explosion limit diagram can be derived from actual production experience or a limited number of experiments, and the safety threshold is determined based on actual production conditions.

[0064] In some embodiments, the security control method further includes the following steps:

[0065] S20: The pressure in the first pipeline 10 is obtained by the pressure monitoring device 9 provided on the first pipeline 10, and the pressure in the furnace of the hot furnace body 52 is obtained by the furnace pressure monitoring device 62. The difference between the pressure in the first pipeline 10 and the pressure in the flame burner 51 is the pressure difference value;

[0066] S21: Compare the pressure difference value with a preset pressure difference threshold. If the pressure difference value is lower than the pressure difference threshold, increase the pressure of the top gas in the first pipeline 10 and / or reduce the pressure of the combustion-supporting gas in the combustion-supporting pipeline 40.

[0067] Specifically, the central controller 6 can calculate, in real time, the pressure differential between the pressure in the first pipeline 10 and the pressure in the furnace of the gas heating furnace 5, and determine whether the pressure differential is above a pressure differential threshold. If the pressure differential between the pressure in the first pipeline 10 and the pressure in the furnace of the gas heating furnace 5 is below the pressure differential threshold, it is necessary to increase the pressure of the gas in the first pipeline 10 and / or reduce the pressure of the combustion-supporting gas in the combustion-supporting pipeline 40 to ensure normal combustion of the flame burner 51 and prevent flames from emitting outward from the furnace.

[0068] In some embodiments, the security control method further includes the following steps:

[0069] S30: Monitor the post-combustion oxygen concentration of the flame burner 51 through the gas composition online monitoring device. If the post-combustion oxygen concentration exceeds the preset oxygen concentration threshold, adjust the flow in the combustion-supporting pipeline 40 and the flow in the first pipeline 10 until the post-combustion oxygen concentration is lower than the oxygen concentration threshold.

[0070] Specifically, the gas composition monitoring device 63 monitors the oxygen concentration of the combustion exhaust gas from the gas heating furnace 5 in real time. If the monitored oxygen concentration exceeds a preset oxygen concentration threshold, it indicates that the combustion in the flame burner 51 is insufficient and the combustion efficiency is low. The central controller 6 controls the flow monitoring and regulating device 7 on the combustion-supporting pipeline 40 and the first pipeline 10 to adjust the flow rates of air and fuel entering the flame burner 51, thereby adjusting the air-fuel ratio until the oxygen concentration of the combustion exhaust gas stabilizes below the oxygen concentration threshold.

[0071] like Figure 5 As shown, in some embodiments, the security control method further includes the following steps:

[0072] S40: Obtain the temperature of the heating furnace body 52 through the temperature monitoring device 64,

[0073] S41: If the temperature of the heating furnace body 52 is lower than or equal to the preset temperature threshold, the first pipeline 10 is opened and the second pipeline 20 is closed, and the heating furnace body 52 is heated by the flame burner 51;

[0074] S42 : If the temperature of the heating furnace body 52 is higher than the temperature threshold, the first pipeline 10 is closed and the second pipeline 20 is opened to heat the gas in the heating furnace body 52 through the heating furnace body 52 .

[0075] Specifically, in this embodiment, there are three gas heating furnaces 5. Two of the gas heating furnaces 5 are in operation, namely, No. 1 gas heating furnace 5 and No. 2 gas heating furnace 5. The other gas heating furnace 5 is in standby mode, namely, No. 3 gas heating furnace 5. If an operating gas heating furnace 5 stops operating due to a fault or other reason, the standby gas heating furnace 5 can be activated to ensure continuous heating of the top gas of multiple furnaces.

[0076] The temperature monitoring device 64, that is, the thermocouple, can monitor in real time the temperature of the gas after heating in the No. 1 gas heating furnace 5. When the gas temperature is lower than the preset temperature threshold, it means that the heat of the No. 1 gas heating furnace 5 is insufficient. At this time, the second pipeline 20 should stop supplying gas to the heating furnace body 52 of the No. 1 gas heating furnace 5, and continue to heat the gas by passing to the No. 2 gas heating furnace 5 to ensure the continuous supply of heating gas to the blast furnace body 1.

[0077] At the same time, the first pipeline 10 and the combustion-supporting pipeline 40 supply gas and air to the flame burner 51 of the No. 1 gas heating furnace 5, and reheat the No. 1 gas heating furnace 5, so as to heat the gas when the temperature of the subsequent No. 2 gas heating furnace 5 is lower than the temperature threshold.

[0078] In some embodiments, the security control method further includes the following steps:

[0079] S50: The pressure value in the third pipeline 30 is obtained by the pressure monitoring device 9 provided on the third pipeline 30. If the pressure value is lower than the preset pressure threshold, it is necessary to increase the pressure by the pressure regulating device 8 provided on the third pipeline 30 until the pressure value meets the pressure threshold.

[0080] Specifically, the pressure monitoring device 9 on the third pipeline 30 monitors the pressure of the gas in the third pipeline 30. If the gas pressure falls below a set pressure, i.e., a pre-set pressure threshold, the pressure regulating device 8 on the third pipeline 30 is used to pressurize the gas in the third pipeline 30. When the gas pressure in the third pipeline 30 meets the pressure threshold, the blast furnace tuyere can be injected. If the pressure regulating device 8 on the third pipeline 30 fails, the central controller 6 can control the hot blast injection pipe 2 to increase the hot blast flow rate to ensure that the tuyere air intake of the blast furnace body 1 remains unchanged.

[0081] The flow monitoring device 65 on the third pipeline 30 is used to monitor whether the flow of the coal gas in the third pipeline 30 reaches the set flow, that is, the pre-set flow threshold. When the flow of the coal gas in the third pipeline 30 does not reach the flow threshold, the central controller 6 can also control the hot air blowing pipe 2 to increase the hot air blowing flow, that is, increase the hot air furnace air volume, so as to ensure that the air inlet air volume of the blast furnace body 1 remains unchanged.

[0082] In this embodiment, the gas heating furnace 5 can adopt a heat exchange type heating furnace or a heat storage type heating furnace. Among them, the flame burner 51 adopts a flat flame burner. The combustion-supporting gas of the gas heating furnace 5 is preheated air, and the gas used as the fuel of the gas heating furnace 5 needs to be preheated. The gas heating furnace 5 is provided with a high-temperature exhaust gas pipeline 60. The high-temperature exhaust gas generated by the gas heating furnace 5 can be directly discharged through the high-temperature exhaust gas pipeline 60, and can also be used to preheat the fuel and combustion-supporting gas of the gas heating furnace 5. The gas used in the carbon cycle blast furnace gas heating and injection system includes but is not limited to blast furnace gas, converter gas, and coke oven gas. The first pipeline 10, the second pipeline 20, the third pipeline 30 and other pipelines need to be wrapped with thermal insulation cotton.

[0083] In practice, the top gas generated by the blast furnace body 1 is output from the furnace roof 3. After dust removal, desulfurization, and power generation, it can enter the flame burner 51 in the gas heating furnace 5 through the first pipeline 10. Together with the combustion-supporting gas entering the flame burner 51 through the combustion-supporting pipeline 40, it is burned in the flame burner 51 to heat the heating furnace body 52. ​​The high-temperature exhaust gas after combustion is discharged through the high-temperature exhaust gas pipeline 60. The discharged exhaust gas can be used to preheat the top gas and combustion-supporting gas entering the flame gas burner.

[0084] The top gas is output from the furnace top 3, and after dust removal, desulfurization, and power generation, it can also pass through the second pipeline 20, enter the heating furnace body 52 after decarbonization in the decarbonization device 4, and the heating furnace body 52 heats the top gas. The heated top gas is injected into the blast furnace body 1 through the third pipeline 30 via the gas injection gun 31.

[0085] To sum up, the present embodiment provides a carbon cycle blast furnace equipped with a blast furnace gas safety control system and a control method thereof. By setting a flame monitoring device 61, a furnace pressure monitoring device 62, a temperature monitoring device 64, a gas composition monitoring device 63, a pressure monitoring device 9, a pressure regulating device 8, a flow monitoring device 65, a flow monitoring and regulating device 7 and a central controller 6, it is possible to monitor and regulate the combustion conditions of the flame burner 51 and the flow and pressure on each pipeline, thereby achieving safe control of the carbon cycle blast furnace, quickly and accurately adjusting the flow and pressure of each gas pipeline and air pipeline, avoiding accidents such as gas leakage, tempering, explosion, etc., increasing the safety performance of the carbon cycle blast furnace, and ensuring safe production operation.

[0086] 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 safety control method for a carbon cycle blast furnace, characterized by: The carbon cycle blast furnace includes a blast furnace body, a gas heating furnace and a central controller; The gas heating furnace includes a flame burner and a heating furnace body. A first pipeline, a second pipeline, and a third pipeline are provided between the blast furnace body and the gas heating furnace. The top of the blast furnace body is connected to the flame burner via the first pipeline, the top of the blast furnace body is connected to the heating furnace body via the second pipeline, and the heating furnace body is connected to the blast furnace body via the third pipeline. The top gas of the blast furnace body enters the flame burner through the first pipeline for combustion, and heats the heating furnace body. When the heating furnace body is heated to meet a preset temperature threshold, the top gas of the blast furnace body enters the heating furnace body through the second pipeline. The heating furnace body heats the top gas. The heated top gas in the heating furnace body enters the blast furnace body through the third pipeline. The flame burner is connected to a combustion-supporting pipeline, and the combustion-supporting gas enters the flame burner through the combustion-supporting pipeline. The gas heating furnace is provided with a flame monitoring device and a furnace pressure monitoring device, and the flame monitoring device and the furnace pressure monitoring device are respectively connected to the central controller by signal; The heating furnace body is provided with a temperature monitoring device and a gas composition monitoring device, and the temperature monitoring device and the gas composition monitoring device are respectively connected to the central controller by signal; The first pipeline, the second pipeline and the combustion-supporting pipeline are all provided with a pressure monitoring device, a pressure regulating device and a flow monitoring and regulating device; the third pipeline is provided with a pressure monitoring device, a pressure regulating device and a flow monitoring device; the pressure monitoring device, the pressure regulating device, the flow monitoring device, the temperature monitoring device, the gas composition monitoring device and the flow monitoring and regulating device are respectively connected to the central controller by signal; The flame monitoring device monitors the combustion condition of the flame burner. If the flame goes out, the current gas composition in the furnace of the heating furnace body is monitored by gas composition, and the safety threshold is determined according to the current gas composition in the furnace of the heating furnace body. Close the first pipeline and increase the flow rate of the combustion-supporting gas in the combustion-supporting pipeline until the gas composition in the furnace of the heating furnace body is lower than the safety threshold and then re-ignite; The pressure in the first pipeline is obtained by a pressure monitoring device provided on the first pipeline, and the pressure in the furnace of the heating furnace body is obtained by the furnace pressure monitoring device, and the difference between the pressure in the first pipeline and the pressure in the furnace of the heating furnace body is the pressure difference value; Comparing the pressure difference value with a preset pressure difference threshold, and if the pressure difference value is lower than the pressure difference threshold, increasing the pressure of the top gas in the first pipeline and / or reducing the pressure of the combustion-supporting gas in the combustion-supporting pipeline; monitoring the oxygen concentration after combustion of the flame burner by an online gas composition monitoring device, and if the oxygen concentration after combustion exceeds a preset oxygen concentration threshold, adjusting the flow rate in the combustion-supporting pipeline and the flow rate in the first pipeline until the oxygen concentration after combustion is lower than the oxygen concentration threshold; The gas heating furnace is provided with a high-temperature waste gas pipeline for discharging high-temperature waste gas or for preheating the fuel and combustion-supporting gas in the gas heating furnace.

2. The safety control method for a carbon cycle blast furnace according to claim 1, characterized in that: There are at least two gas heating furnaces, the top of the blast furnace body is connected to each of the flame burners through the first pipeline, the top of the blast furnace body is connected to each of the heating furnace bodies through the second pipeline, and each of the heating furnace bodies is connected to the blast furnace body through the third pipeline.

3. The safety control method for a carbon cycle blast furnace according to claim 2, characterized in that: There are three gas heating furnaces.

4. The safety control method for a carbon cycle blast furnace according to claim 1, characterized in that: The second pipeline is provided with a carbon removal device, which is used to remove carbon dioxide from the top gas.

5. The safety control method for a carbon cycle blast furnace according to claim 1, characterized in that: The second pipeline is also connected to the surplus gas pipeline, and the gas in the surplus gas pipeline enters the heating furnace body through the second pipeline.

6. The safety control method for a carbon cycle blast furnace according to claim 1, comprising the following steps: The temperature of the heating furnace body is obtained through the temperature monitoring device. If the temperature of the heating furnace body is lower than or equal to the temperature threshold, the first pipeline is opened and the second pipeline is closed to heat the heating furnace body through the flame burner; If the temperature of the heating furnace body is higher than a preset temperature threshold, the first pipeline is closed and the second pipeline is opened to heat the coal gas in the heating furnace body through the heating furnace body.

7. A safety control method for a carbon cycle blast furnace according to claim 6, comprising the following steps: The pressure value in the third pipeline is obtained by a pressure monitoring device arranged on the third pipeline. If the pressure value is lower than a preset pressure threshold, it is necessary to increase the pressure by a pressure regulating device arranged on the third pipeline until the pressure value meets the pressure threshold.

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