Hydrogen metallurgy hydrogen-rich gas heating and furnace top gas recycling system

Abstract

This utility model discloses a hydrogen-rich gas heating and furnace top gas recycling system for hydrogen metallurgy, including a hydrogen metallurgical vertical shaft furnace, a heat exchange and cooling device, a dust removal device, a drying and dehydration device, a CO2 separation and purification device, and a regenerative heating furnace. The furnace top gas outlet of the hydrogen metallurgical vertical shaft furnace is sequentially connected to the heat exchange and cooling device, the dust removal device, the drying and dehydration device, and the CO2 separation and purification device. The regenerative heating furnace includes a combustion chamber and a regenerator chamber. The combustion chamber has a gas inlet and a flue gas outlet, and the regenerator chamber has a flue gas passage and a process gas passage. The flue gas outlet of the combustion chamber is connected to the flue gas inlet of the regenerator chamber's flue gas passage. The lean CO2 gas outlet of the CO2 separation and purification device is connected to the gas inlet of the combustion chamber. The process gas inlet of the regenerator chamber's process gas passage is connected to a hydrogen-rich process gas pipeline, and the process gas outlet is connected to the process gas inlet of the hydrogen metallurgical vertical shaft furnace. This system has advantages such as high thermal efficiency, safety and reliability, simple operation, and effective utilization of exhaust gas.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen-based direct reduction ironmaking technology, and in particular to a hydrogen-rich gas heating and furnace top gas recycling system in hydrogen metallurgy. Background Technology

[0002] Hydrogen-based direct reduction ironmaking technology has attracted widespread attention as a new CO2 emission reduction technology in hydrogen metallurgy, with the heating of process gas being crucial. Currently, the main heating method for process gas in hydrogen metallurgy is through tubular furnaces. However, the uneven temperature distribution of the combustion flame in these furnaces leads to coking and carbon precipitation inside the furnace tubes, which is detrimental to the long-term stable operation of the furnace and affects the lifespan of the furnace tubes. Furthermore, the heating capacity of the furnaces is limited, reaching a maximum of 950℃, resulting in high energy consumption and large carbon emissions, which is not conducive to energy conservation and emission reduction.

[0003] To address the aforementioned issues, patent application CN116814886A proposed a hydrogen metallurgical gas-based direct reduction system and process, as well as a process gas heating furnace. The process gas is primarily heated using an oxygen-enriched burner combustion tube furnace. However, it fails to solve the problem of limited heating capacity, with a maximum temperature of only 950°C. Furthermore, safety control during the heating process is challenging, and improper control could lead to accidents such as fires and explosions. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a hydrogen-rich gas heating and furnace top gas recycling system for hydrogen metallurgy with good heating effect.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows: It includes a hydrogen metallurgical vertical shaft furnace, a heat exchange and cooling device, a dust removal device, a drying and dehydration device, a CO2 separation and purification device, and a regenerative heating furnace; the gas outlet at the top of the hydrogen metallurgical vertical shaft furnace is sequentially connected to the heat exchange and cooling device, the dust removal device, the drying and dehydration device, and the CO2 separation and purification device; the regenerative heating furnace includes a combustion chamber and a regenerator chamber; the combustion chamber is provided with a gas inlet and a flue gas outlet, and the regenerator chamber is provided with a flue gas passage and a process gas passage; the flue gas outlet of the combustion chamber is connected to the flue gas inlet of the flue gas passage of the regenerator chamber; the lean CO2 gas outlet of the CO2 separation and purification device is connected to the gas inlet of the combustion chamber; the process gas inlet of the process gas passage of the regenerator chamber is connected to a hydrogen-rich process gas pipeline, and the process gas outlet is connected to the process gas inlet of the hydrogen metallurgical vertical shaft furnace.

[0006] Furthermore, the combustion chamber is also provided with an air inlet, which is connected to an induced draft fan that supplies air into the combustion chamber.

[0007] Furthermore, the flue gas outlet of the heat storage chamber flue gas passage is connected to an induced draft fan for dissipation.

[0008] Furthermore, a gas mixing device is also provided; the gas mixing device is connected between the combustion chamber of the CO2 separation and purification device and the regenerative heating furnace, and the inlet of the gas mixing device is also connected to a combustible gas pipeline.

[0009] Furthermore, a compressor is provided between the drying and dehydration device and the CO2 separation and purification device, a compressor is provided at the gas inlet end of the combustion chamber of the regenerative heating furnace, and the process gas inlet of the regenerative chamber is connected to the hydrogen-rich process gas pipeline through a compressor.

[0010] Furthermore, the heat storage chamber flue gas passage and the process gas passage share the same inlet, which is equipped with a reversing valve; the reversing valve controls the connection between the combustion chamber flue gas outlet and the heat storage chamber flue gas passage, as well as the connection between the hydrogen-rich process gas pipeline and the heat storage chamber process gas passage.

[0011] Furthermore, the flue gas inlet of the heat storage chamber flue gas passage is equipped with a control valve, and the process gas inlet of the process gas passage is equipped with a control valve.

[0012] The beneficial effects of adopting the above technical solution are as follows: This utility model uses a regenerative heating furnace, and the regenerative chamber mainly uses checker bricks for heat storage. Checker bricks have the advantages of large heat storage area, strong heat exchange capacity, no coking and carbon precipitation problems, and the regenerative chamber can heat the process gas to above 900°C. The generated furnace top gas is returned to the combustion chamber for recycling. It solves the problems of limited heating temperature in existing tubular heating furnaces and has the advantages of high thermal efficiency, safety and reliability, simple operation, and effective utilization of tail gas. Attached Figure Description

[0013] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0014] Figure 1 This is a schematic diagram of the structure of this utility model. Detailed Implementation

[0015] Figure 1As shown, the hydrogen-rich gas heating and furnace top gas recycling system in this hydrogen metallurgical process includes a hydrogen metallurgical vertical shaft furnace, a heat exchange and cooling device, a dust removal device, a drying and dehydration device, a CO2 separation and purification device, a gas mixing device, a regenerative heating furnace, and a compressor. The furnace top gas outlet of the hydrogen metallurgical vertical shaft furnace is connected to the inlet of the heat exchange and cooling device; the outlet of the heat exchange and cooling device is connected to the inlet of the dust removal device; the outlet of the dust removal device is connected to the inlet of the drying and dehydration device; the outlet of the drying and dehydration device is connected to the inlet of the CO2 separation and purification device; a compressor is installed on the pipeline between the drying and dehydration device and the CO2 separation and purification device. The CO2 separation and purification device has a rich CO2 gas outlet and a lean CO2 gas outlet; the lean CO2 gas outlet of the CO2 separation and purification device is connected to the inlet of the gas mixing device; the outlet of the gas mixing device is connected to the regenerative heating furnace; a second compressor is installed on the pipeline between the gas mixing device and the regenerative heating furnace; the inlet of the gas mixing device is also connected to a combustible gas pipeline.

[0016] This hydrogen metallurgical system for hydrogen-rich gas heating and furnace top gas circulation includes a regenerative heating furnace comprising a combustion chamber and a regenerator chamber. The combustion chamber has a gas inlet, a flue gas outlet, and an air inlet. The regenerator chamber has a flue gas passage and a process gas passage, which are not interconnected. The lean CO2 gas outlet of the CO2 separation and purification unit is connected to the gas inlet of the combustion chamber via a mixing device and a second compressor. The flue gas outlet of the combustion chamber is connected to the flue gas inlet of the regenerator chamber's flue gas passage. The flue gas outlet of the regenerator chamber's flue gas passage is connected to an induced draft fan, which draws out and releases the flue gas from the regenerator chamber's flue gas passage. The air inlet of the combustion chamber is connected to an induced draft fan, which supplies air to the combustion chamber. The process gas inlet of the regenerator chamber's process gas passage is connected to a hydrogen-rich process gas pipeline via a third compressor, and the process gas outlet is connected to the process gas inlet of the hydrogen metallurgical vertical shaft furnace.

[0017] The flue gas passage and process gas passage of the regenerator can share the same inlet, or they can each have a separate inlet. When the flue gas passage and process gas passage share the same inlet, both the flue gas inlet and the process gas inlet are the same. This inlet is equipped with a reversing valve, which controls the connection between the flue gas outlet of the combustion chamber and the flue gas passage of the regenerator, as well as the connection between the hydrogen-rich process gas pipeline and the process gas passage of the regenerator. When the flue gas passage and process gas passage each have a separate inlet, both are independent inlets, equipped with control valves.

[0018] In this hydrogen metallurgical system for heating hydrogen-rich gas and recycling furnace top gas, the regenerator furnace's regenerator chambers are constructed using checker bricks made of a high-temperature and hydrogen-corrosion-resistant material. Each combustion chamber of the regenerator furnace is equipped with either two or three regenerator chambers. When using two regenerator chambers, while the first chamber is undergoing heat exchange with the high-temperature checker bricks, the second chamber is heating the checker bricks. The two chambers operate alternately, ensuring a continuous supply of the required hot, hydrogen-rich process gas to the hydrogen metallurgical furnace. When using three regenerator chambers, the heat exchange between the three chambers is staggered and cross-checked.

[0019] In this hydrogen-rich gas heating and furnace top gas recycling system for hydrogen metallurgy, flow control valves are installed on the pipelines between the gas mixing device and the combustible gas pipeline, and also on the pipelines between the CO2 separation and purification device and the gas mixing device. These valves are used to regulate the gas composition ratio within the gas mixing device to meet the requirements for the furnace gas intake. A flow control valve is also installed on the outlet pipeline of the gas mixing device to regulate the ratio of furnace gas to combustion air to meet the combustion requirements of the combustion chamber.

[0020] Figure 1 As shown. The operation process of the hydrogen-rich gas heating and furnace top gas recycling system in this hydrogen metallurgy is as follows:

[0021] (1) The lean CO2 gas produced by the furnace top gas of the hydrogen metallurgical furnace after heat exchange cooling, dust removal and purification, drying and dehydration and CO2 separation and purification is mixed with coke oven gas, compressed and then enters the combustion chamber of the regenerative heating furnace. At the same time, air is introduced by the induced draft fan for combustion and combustion assistance. The generated high temperature flue gas of 1050℃ enters the flue gas passage of the regenerative heating furnace through the pipeline.

[0022] (2) When the high-temperature flue gas passes through the flue gas passage of the heat storage chamber of the heating furnace, the checker bricks of the heat storage chamber are heated to 950°C through heat exchange for heat storage. After heat exchange, the flue gas temperature drops to below 300°C and is drawn out by the induced draft fan for release.

[0023] (3) At this time, the reversing valve is activated, or the flue gas inlet control valve is closed and the process gas inlet control valve is opened to cut off the flue gas supply. The hydrogen-rich process gas enters the process gas channel of the heat storage chamber. After absorbing the heat of the heat storage chamber checker bricks, the hydrogen-rich process gas rises to 900°C.

[0024] (4) The heated hydrogen-rich process gas enters the process gas inlet of the hydrogen metallurgical shaft furnace through the process gas outlet of the regenerator process gas channel via a pipeline to reduce iron ore. After the reduction reaction is completed, the furnace top gas is cooled by heat exchange, dust removal and purification, drying and dehydration, and CO2 separation and purification. The resulting lean CO2 gas is mixed with coke oven gas, compressed and then enters the combustion chamber of the regenerator for recycling.

[0025] (5) The top gas of the hydrogen metallurgical vertical furnace can also be processed by the circulation treatment system and then sent back to the hydrogen metallurgical vertical furnace as process gas for recycling.

Claims

1. A hydrogen-rich gas heating and furnace top gas recycling system for hydrogen metallurgy, characterized in that: The system includes a hydrogen metallurgical shaft furnace, a heat exchange and cooling device, a dust removal device, a drying and dehydration device, a CO2 separation and purification device, and a regenerative heating furnace. The top gas outlet of the hydrogen metallurgical shaft furnace is sequentially connected to the heat exchange and cooling device, the dust removal device, the drying and dehydration device, and the CO2 separation and purification device. The regenerative heating furnace includes a combustion chamber and a regenerator chamber. The combustion chamber has a gas inlet and a flue gas outlet, while the regenerator chamber has a flue gas passage and a process gas passage. The flue gas outlet of the combustion chamber is connected to the flue gas inlet of the regenerator chamber's flue gas passage. The lean CO2 gas outlet of the CO2 separation and purification device is connected to the gas inlet of the combustion chamber. The process gas inlet of the regenerator chamber's process gas passage is connected to a hydrogen-rich process gas pipeline, and the process gas outlet is connected to the process gas inlet of the hydrogen metallurgical shaft furnace.

2. The hydrogen-rich gas heating and furnace top gas recycling system in hydrogen metallurgy according to claim 1, characterized in that: The combustion chamber is also equipped with an air inlet, which is connected to an induced draft fan that supplies air into the combustion chamber.

3. The hydrogen-rich gas heating and furnace top gas recycling system in hydrogen metallurgy according to claim 1, characterized in that: The flue gas outlet of the heat storage chamber flue gas passage is connected to an induced draft fan for venting.

4. The hydrogen-rich gas heating and furnace top gas recycling system in hydrogen metallurgy according to claim 1, characterized in that: It is also equipped with a gas mixing device; the gas mixing device is connected between the combustion chamber of the CO2 separation and purification device and the regenerative heating furnace, and the inlet of the gas mixing device is also connected to the combustible gas pipeline.

5. A hydrogen-rich gas heating and furnace top gas recycling system in hydrogen metallurgy according to claim 1, characterized in that: A compressor is installed between the drying and dehydration device and the CO2 separation and purification device. A compressor is installed at the gas inlet end of the regenerative heating furnace combustion chamber. The process gas inlet of the regenerative chamber is connected to the hydrogen-rich process gas pipeline through a compressor.

6. A hydrogen-rich gas heating and furnace top gas recycling system in hydrogen metallurgy according to any one of claims 1-5, characterized in that: The heat storage chamber flue gas passage and the process gas passage share the same inlet, which is equipped with a reversing valve. The reversing valve controls the connection between the combustion chamber flue gas outlet and the heat storage chamber flue gas passage, as well as the connection between the hydrogen-rich process gas pipeline and the heat storage chamber process gas passage.

7. A hydrogen-rich gas heating and furnace top gas recycling system in hydrogen metallurgy according to any one of claims 1-5, characterized in that: The flue gas inlet of the heat storage chamber flue gas passage is equipped with a control valve, and the process gas inlet of the process gas passage is equipped with a control valve.

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