A method and system for optimizing the temperature field of an initial coal gas stream of a hydrogen-rich smelting blast furnace

Abstract

The application discloses a hydrogen-rich smelting blast furnace initial coal gas flow temperature field optimization method and system. The method comprises the following steps: controlling hydrogen-rich gas, coal powder and coke to be sequentially combusted in front of tuyere; regarding the front of the tuyere as an adiabatic environment, collecting blast furnace tuyere data; calculating the theoretical combustion temperature of the front of all tuyeres of the blast furnace; under the premise of ensuring the total coal powder injection amount, gradually reducing the coal powder injection amount of the hydrogen injection tuyere, and increasing the coal powder injection amount of the tuyere without hydrogen injection until the absolute error of the calculated theoretical combustion temperature T0 of the hydrogen injection tuyere and the theoretical combustion temperature T1 of the tuyere without hydrogen injection is less than the set error threshold. The method can effectively improve the uneven distribution of hydrogen cold-state injection of the initial gas flow of the blast furnace through analysis of the blast furnace tuyere data.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking, and in particular to a method and system for optimizing the initial gas flow temperature field of a hydrogen-rich blast furnace. Background Technology

[0002] In the new technologies of the steel industry, using hydrogen to replace carbon as a reducing agent in blast furnaces not only improves blast furnace efficiency and ensures stable operation, but also significantly reduces carbon emissions due to the reaction product being water. Therefore, hydrogen-enriched blast furnace smelting is one of the main technologies for blast furnace smelting and a major research area for large steel conglomerates. However, current hydrogen injection is mainly cold-state, which significantly reduces the theoretical combustion temperature at the hydrogen injection tuyeres. Combined with the fact that hydrogen-enriched smelting typically increases the oxygen enrichment rate of the blast furnace, this further leads to a difference in theoretical combustion temperature between hydrogen-injected and non-hydrogen-injected tuyeres, resulting in uneven initial gas flow temperature distribution and affecting the initial gas flow distribution in the blast furnace.

[0003] Therefore, developing an optimization method for the initial gas flow temperature field of a hydrogen-rich blast furnace is an urgent problem to be solved. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides an optimization method for the initial gas flow temperature field of a hydrogen-rich blast furnace, thereby improving the uneven distribution of the initial gas flow in a hydrogen-cold-injected blast furnace.

[0005] The technical solution is as follows:

[0006] A method for optimizing the initial gas flow temperature field of a hydrogen-rich blast furnace includes:

[0007] Step S1: Control the hydrogen-rich gas, pulverized coal, and coke to burn in the set sequence at the front end of the tuyeres;

[0008] Step S2: Collect data from each tuyeres of the blast furnace;

[0009] Step S3: Treat the tuyeres front end swirling zone as an adiabatic environment and calculate the theoretical combustion temperature of all tuyeres front ends in the blast furnace;

[0010] Step S4: Compare the theoretical combustion temperatures of the hydrogen-injected duct and the non-hydrogen-injected duct. While ensuring the total pulverized coal injection rate, gradually reduce the pulverized coal injection rate of the hydrogen-injected duct and increase the pulverized coal injection rate of the non-hydrogen-injected duct until the absolute error between the calculated theoretical combustion temperature T0 of the hydrogen-injected duct and the theoretical combustion temperature T1 of the non-hydrogen-injected duct is less than the set error threshold.

[0011] Furthermore, the error threshold is 0.1℃.

[0012] Furthermore, the blast furnace tuyeres data includes the flow rate of hydrogen-rich gas, the flow rate of cold air, the temperature of hot air, the pressure of hot air, the composition of the injected hydrogen-rich gas, the oxygen enrichment rate and oxygen content of the blast furnace, the composition of coke, the composition of injected pulverized coal, the amount of pulverized coal injected, the number of blast furnace tuyeres and the location of hydrogen injection tuyeres, the temperature of hydrogen-rich gas and the humidity of the blast air.

[0013] Furthermore, the formula for calculating the theoretical combustion temperature is:

[0014] T f =(Q C +Q BV +Q coke +Q gas -Q w -Q crack ) / (c P,CO,tf ×V CO +c P,N2,tf ×V N2 +c P,H2,tf ×V H2 )

[0015] In the formula, Q C The carbon combustion in front of the vent produces CO, releasing heat; Q BV To bring in heat through the blower; Q coke Heat is introduced into the coke; Q w The heat consumed is due to the decomposition of moisture in the blower air; Q crack The heat consumed by the decomposition of hydrocarbons in pulverized coal and hydrogen-rich gas; Q gas To introduce heat into the gas; c P,CO,tf c P,N2,tf c P,H2,tf V represents the specific heat capacity of CO, N2, and H2 at the theoretical combustion temperature, respectively. CO V N2 V H2 These represent the volumes of CO, N2, and H2 at the front end of the air vent.

[0016] This invention also provides an optimized initial gas flow temperature distribution system for hydrogen-rich blast furnaces, involving a blast furnace data acquisition system, a theoretical combustion temperature calculation system, a tuyere pulverized coal injection flow control system, and an alarm system;

[0017] The data acquisition system is used to collect data from each tuyeres of the blast furnace;

[0018] The theoretical combustion temperature calculation system is used to calculate the theoretical combustion temperature at the front end of all tuyeres in the blast furnace based on the blast furnace tuyere data.

[0019] The tuyere pulverized coal flow control system is used to control the combustion of hydrogen-rich gas, pulverized coal, and coke in a set sequence at the front end of the tuyere.

[0020] The alarm system is connected to the theoretical combustion temperature calculation system and is used to provide operation prompts and abnormal alarm information.

[0021] Furthermore, the data acquisition system includes sensors for collecting data on the flow rate of hydrogen-rich gas, cold air flow rate, hot air temperature, hot air pressure, composition of injected hydrogen-rich gas, blast furnace oxygen enrichment rate and oxygen content, coke composition, composition of injected pulverized coal, pulverized coal injection volume, number of blast furnace tuyeres and location of hydrogen-rich gas injection tuyeres, temperature of hydrogen-rich gas and humidity of blast air.

[0022] Beneficial effects:

[0023] This invention provides an optimization method for the initial gas flow temperature field of a hydrogen-rich blast furnace. Based on the analysis of blast furnace tuyeres data, it can effectively improve the uneven distribution of the initial gas flow in a blast furnace with cold hydrogen injection. Attached Figure Description

[0024] Figure 1 This is a system block diagram of the optimization system for the initial gas flow temperature field of the hydrogen-rich blast furnace of the present invention.

[0025] Figure 2 This invention relates to the calculation logic for the theoretical combustion temperature at the front end of all tuyeres in the blast furnace. Detailed Implementation

[0026] To further illustrate the various embodiments, the present invention provides accompanying drawings. These drawings are part of the disclosure of the present invention, primarily used to illustrate the embodiments, and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these drawings, those skilled in the art should be able to understand other possible implementations and the advantages of the present invention.

[0027] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.

[0028] like Figure 1 As shown, this invention provides an optimization system for the initial gas flow temperature field of a hydrogen-rich blast furnace, involving systems such as a blast furnace data acquisition system, a theoretical combustion temperature calculation system, a tuyere pulverized coal injection flow control system, and an alarm system.

[0029] The data acquisition system includes numerous temperature sensors, flow sensors, and pressure sensors installed at and around the blast furnace tuyeres to collect data from each tuyer in the hydrogen-rich blast furnace. This data includes, but is not limited to, the flow rate of hydrogen-rich gas, cold blast flow rate, hot blast temperature, hot blast pressure, composition of injected hydrogen-rich gas, blast furnace oxygen enrichment rate and quantity, coke composition, composition of injected pulverized coal, pulverized coal injection quantity, number of blast furnace tuyeres, location of hydrogen-rich gas injection tuyeres, temperature of hydrogen-rich gas, and blast humidity. This data is stored in a database for use by the theoretical combustion temperature calculation system. The cold blast flow rate, oxygen enrichment quantity, and pulverized coal injection quantity are calculated from the data collected by the PLC, combined with the number of blast furnace tuyeres, to determine the data at the front end of each individual tuyer. The hydrogen enrichment quantity of a single tuyer is calculated based on the total hydrogen enrichment quantity of the blast furnace and the number of hydrogen-rich tuyeres.

[0030] The theoretical combustion temperature calculation system calculates the theoretical combustion temperature at the front end of all tuyeres in the blast furnace based on data collected by the data acquisition system. This system is connected to the tuyer pulverized coal injection flow control system, and adjusts the pulverized coal injection rate at each tuyer according to the combustion temperature until the temperature at the front end of all tuyeres is uniform.

[0031] The tuyere pulverized coal flow control system is part of the blast furnace's PLC control system, which controls the combustion of hydrogen-rich gas, pulverized coal, and coke in a set sequence at the front end of the tuyere.

[0032] The alarm system is connected to the theoretical combustion temperature calculation system; when the collected data is normal, it provides operation prompts; when the collected data is abnormal, it issues an alarm and displays the blast furnace's temperature and status information to the operator.

[0033] This invention provides a method for optimizing the initial gas flow temperature field of a hydrogen-rich blast furnace, comprising the following steps:

[0034] Step S1: Control the hydrogen-rich gas, pulverized coal, and coke to burn in the set sequence at the front end of the tuyeres.

[0035] Step S2: Collect data from each tuyeres of the blast furnace. The tuyeres data includes, but is not limited to, the flow rate of hydrogen-rich gas, the flow rate of cold air, the temperature of hot air, the pressure of hot air, the composition of the injected hydrogen-rich gas, the oxygen enrichment rate and oxygen content of the blast furnace, the composition of coke, the composition of injected pulverized coal, the amount of pulverized coal injected, the number of blast furnace tuyeres and the location of the hydrogen-rich gas injection tuyeres, the temperature of the hydrogen-rich gas and the humidity of the blast air.

[0036] Step S3: Treat the tuyere front end swirling zone as an adiabatic environment, and calculate the theoretical combustion temperature of each tuyere front end of the blast furnace based on the tuyere data.

[0037] In this embodiment, the theoretical combustion temperature is calculated using the heat balance method of the air vent area, and the formula is: T f =(Q C +QBV +Q coke +Q gas -Q w -Q crack ) / (c P,CO,tf ×V CO +c P,N2,tf ×V N2 +C P,H2,tf ×V H2 )

[0038] In the formula, Q C The carbon combustion in front of the vent produces CO, releasing heat; Q BV To bring in heat through the blower; Q coke Heat is introduced into the coke; Q w The heat consumed is due to the decomposition of moisture in the blower air; Q crack The heat consumed by the decomposition of hydrocarbons in pulverized coal and hydrogen-rich gas; Q gas The gas introduces heat; C P,CO,tf c P,N2,tf C P,H2,tf V represents the specific heat capacity of CO, N2, and H2 at the theoretical combustion temperature, respectively. CO V N2 V H2 These represent the volumes of CO, N2, and H2 at the vent front end, respectively. The specific heat capacity of the gas is a function of temperature and is calculated using a cyclic approximation method. The volumes of CO, N2, and H2 at the vent front end can be obtained by statistically analyzing vent data such as the flow rate of hydrogen-rich gas, the flow rate of cold air, and the composition of the injected hydrogen-rich gas.

[0039] Step S4: Compare the theoretical combustion temperatures of the hydrogen-injected duct and the non-hydrogen-injected duct. While ensuring the total pulverized coal injection rate, gradually reduce the injection rate of the hydrogen-injected duct while increasing the injection rate of the non-hydrogen-injected duct until the absolute error between the calculated theoretical combustion temperature T0 of the hydrogen-injected duct and the theoretical combustion temperature T1 of the non-hydrogen-injected duct is less than a set error threshold (preferably set to 0.1℃ in this embodiment). The final theoretical combustion temperature Tf is then output. This method solves the problem that the temperature at the front end of the hydrogen-injected duct is lower than that of the non-hydrogen-injected duct, and that the difference further increases with the increase of the hydrogen injection rate.

[0040] Its specific calculation logic is as follows: Figure 2 As shown, if the calculated theoretical combustion temperature is lower than the specified threshold, the operator is prompted that the theoretical combustion temperature is too low and the oxygen enrichment rate can be appropriately increased. The calculation results are sent to the pulverized coal injection control system at the tuyere, which performs precise dynamic control of the pulverized coal at each tuyere to achieve uniform temperature at the front end of all tuyeres.

[0041] Compared with existing technologies, the present invention has the following advantages:

[0042] (1) By controlling the amount of pulverized coal at the front end of each tuyer in the blast furnace, the initial gas flow temperature becomes more uniform while ensuring that the thermal regime of the blast furnace remains unchanged.

[0043] (2) It can dynamically control the theoretical combustion temperature according to the different hydrogen injection amounts in the blast furnace. At the same time, it can trigger an alarm when the theoretical temperature is too low due to excessive hydrogen injection, so that the blast furnace can achieve stability, efficiency and green operation in hydrogen-rich smelting.

[0044] Although the invention has been specifically shown and described in conjunction with preferred embodiments, those skilled in the art should understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined in the appended claims, all of which shall be within the scope of protection of the invention.

Claims

1. A method for optimizing the initial gas flow temperature field of a hydrogen-rich blast furnace, characterized in that, include: Step S1: Control the hydrogen-rich gas, pulverized coal, and coke to burn in the set sequence at the front end of the tuyeres; Step S2: Collect data from each tuyeres of the blast furnace; Step S3: Treat the tuyeres front end swirling zone as an adiabatic environment and calculate the theoretical combustion temperature of all tuyeres front ends in the blast furnace; Step S4: Compare the theoretical combustion temperatures of the hydrogen-injected duct and the non-hydrogen-injected duct. While ensuring the total pulverized coal injection rate, gradually reduce the pulverized coal injection rate of the hydrogen-injected duct and increase the pulverized coal injection rate of the non-hydrogen-injected duct until the absolute error between the calculated theoretical combustion temperature T0 of the hydrogen-injected duct and the theoretical combustion temperature T1 of the non-hydrogen-injected duct is less than the set error threshold.

2. The method for optimizing the initial gas flow temperature field of a hydrogen-rich blast furnace as described in claim 1, characterized in that: The error threshold is 0.1℃.

3. The method for optimizing the initial gas flow temperature field of a hydrogen-rich blast furnace as described in claim 1, characterized in that: The tuyeres data includes the flow rate of hydrogen-rich gas, the flow rate of cold air, the temperature of hot air, the pressure of hot air, the composition of the injected hydrogen-rich gas, the oxygen enrichment rate and oxygen content of the blast furnace, the composition of coke, the composition of injected pulverized coal, the amount of pulverized coal injected, the number of blast furnace tuyeres and the location of hydrogen injection tuyeres, the temperature of hydrogen-rich gas and the humidity of the blower air.

4. The method for optimizing the initial gas flow temperature field of a hydrogen-rich blast furnace as described in claim 3, characterized in that: The formula for calculating the theoretical combustion temperature is as follows: In the formula, Q C The carbon combustion in front of the air vent generates CO and releases heat. Q BV To bring in heat through the blower; Q coke To introduce heat into the coke; Q w The heat consumed is due to the decomposition of moisture in the blower air; Q crack The heat consumed in the decomposition of hydrocarbons in pulverized coal and hydrogen-rich gas; Q gas To introduce heat into the gas; , , These are the specific heat capacities of CO, N2, and H2 at the theoretical combustion temperature, respectively. , , These represent the volumes of CO, N2, and H2 at the front end of the air vent.

5. An optimization system for the initial gas flow temperature field of a hydrogen-rich blast furnace, used to implement the optimization method for the initial gas flow temperature field of a hydrogen-rich blast furnace as described in any one of claims 1-4, characterized in that: This includes the blast furnace data acquisition system, theoretical combustion temperature calculation system, tuyere pulverized coal injection flow control system, and alarm system; The data acquisition system is used to collect data from each tuyeres of the blast furnace; The theoretical combustion temperature calculation system is used to calculate the theoretical combustion temperature at the front end of all tuyeres in the blast furnace based on the blast furnace tuyere data. The tuyere pulverized coal flow control system is used to control the combustion of hydrogen-rich gas, pulverized coal, and coke in a set sequence at the front end of the tuyere. The alarm system is connected to the theoretical combustion temperature calculation system and is used to provide operation prompts and abnormal alarm information.

6. The optimization system for the initial gas flow temperature field of a hydrogen-rich blast furnace as described in claim 5, characterized in that: The data acquisition system includes sensors for collecting data on the flow rate of hydrogen-rich gas, cold air flow rate, hot air temperature, hot air pressure, composition of injected hydrogen-rich gas, blast furnace oxygen enrichment rate and oxygen content, coke composition, composition of injected pulverized coal, pulverized coal injection volume, number of blast furnace tuyeres and location of hydrogen-rich gas injection tuyeres, temperature of hydrogen-rich gas, and humidity of blast air.

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