Hydrogen production by electrolysis of water

Abstract

The application belongs to the technical field of blast furnace ironmaking, and specifically discloses a HyCROF furnace tuyere small sleeve and an operation control method, which comprises a small sleeve body, a coal gas main passage, an oxygen inner passage and a cooling water passage are arranged on the small sleeve body, a wear-resistant lining layer is arranged on the front end surface of the small sleeve body, the small sleeve coal gas main passage is located at the center of the small sleeve body, the oxygen inner passage is welded with an oxygen outer passage, and the oxygen outer passage is obliquely arranged and extends into the small sleeve coal gas main passage. In view of the problem of serious burning loss of the front end of the tuyere, the application realizes double optimization of structure and material, and insulates the tuyere end surface from the direct impact of the combustion heat load from the hardware level; meanwhile, the coal gas flow rate and the oxygen outlet flow rate are precisely controlled, and the high-temperature reaction zone of the coal gas and the oxygen is moved to a position away from the tuyere end surface in the furnace, so that the problem that the existing HyCROF furnace tuyere small sleeve is seriously burned at the front end due to the fact that the high-temperature combustion zone of the coal gas and the oxygen is close to the tuyere end surface, thereby affecting the production efficiency.

Description

Technical Field

[0001] This invention relates to the field of blast furnace ironmaking technology, specifically to a HyCROF furnace tuyeres sleeve and its operation control method. Background Technology

[0002] The HyCROF process, a crucial technique for intensifying blast furnace ironmaking, increases production and reduces costs by injecting high-temperature gas, oxygen, and pulverized coal into the furnace. The tuyere sleeve is the core injection component of this process, and its performance directly impacts blast furnace production stability and capacity release. The front end of the tuyere sleeve directly faces the molten slag and iron in the furnace at temperatures exceeding 2000°C, while high-temperature reducing gas at 1200°C flows through it. Simultaneously, oxygen is injected through the tuyere channel. The component is subjected to multiple effects over long periods, including ultra-high temperature heat radiation, slag erosion, and oxidation.

[0003] In existing traditional HyCROF tuyer sleeves, the oxygen nozzle is positioned too close to the tuyer end face. After oxygen enters the gas passage, it undergoes a violent oxidation and combustion reaction with the high-temperature gas near the tuyer end face. Due to airflow backflow, some gas stagnates in the tuyer end face area. After the gas and oxygen fully react, a localized high-temperature zone is formed. This high-temperature combustion zone is highly concentrated at the front end of the tuyer, far exceeding the tolerance temperature of the tuyer substrate. Consequently, this leads to erosion, peeling, perforation, and other burn-off failures on the tuyer end face and the oxygen extension passage.

[0004] If the tuyeres burn out, it will alter the injection flow field of coal gas and oxygen, disrupting the combustion reaction balance within the furnace and causing a deterioration in smelting indicators. Severe burnout necessitates unplanned shutdowns to replace tuyeres, increasing spare parts consumption and maintenance costs, interrupting continuous blast furnace production, and directly limiting the capacity utilization of the HyCROF process. Simultaneously, existing technologies lack operational control specifications tailored to the tuyeres structure, fail to establish outlet flow rate constraints for coal gas and oxygen injection, and lack standardized operating procedures for nitrogen purging protection. Under low-speed conditions, oxygen is prone to accumulate in the channel, causing backfire and erosion of the pipeline. In abnormal emergency conditions, the lack of standardized media control sequences, failure to promptly cut off oxygen supply after a sudden drop in oxygen flow rate, and the absence of continuous nitrogen protection further exacerbate the risk of oxygen channel burnout failure.

[0005] In summary, to solve the above problems, it is necessary to design a HyCROF furnace tuyere sleeve and its operation control method to address the issue that the existing HyCROF furnace tuyere sleeve suffers severe burn-out at the front end of the tuyere due to the proximity of the high-temperature combustion zone of gas and oxygen to the tuyere end face, thus affecting production efficiency. Summary of the Invention

[0006] The purpose of this invention is to provide a HyCROF furnace tuyer sleeve and its operation control method to solve the problem that the existing HyCROF furnace tuyer sleeve suffers severe burn-out at the front end of the tuyer due to the proximity of the high-temperature zone of gas and oxygen combustion to the tuyer end face, thus affecting production efficiency.

[0007] To achieve the above objectives, the basic solution provided by this invention is as follows: a HyCROF furnace tuyeres sleeve, comprising a sleeve body, wherein the sleeve body is provided with a main gas channel, an oxygen channel, and a cooling water channel; the front end face of the sleeve body and the main gas channel are provided with wear-resistant linings along the gas outlet direction, the wear-resistant linings being 2-3 mm thick and 55 mm long; the rear end face of the sleeve body is provided with a cooling water inlet and a cooling water outlet; the main gas channel is located at the center of the sleeve body; the oxygen channel includes an inner oxygen channel and an outer oxygen channel, the outer oxygen channel being welded to the inner oxygen channel; the outer oxygen channel being inclined and extending into the main gas channel; and a flow guide is provided in the cooling water channel.

[0008] The beneficial effects of the present invention are as follows: (1) The present invention adopts a split oxygen dual-channel structure and is reinforced with local cobalt-based alloy material for protection. The oxygen inner channel is made of copper pipe to ensure heat conduction and cooling effect. The oxygen outer channel is made of cobalt-based alloy with a temperature resistance of over 1100℃. At the same time, the oxygen outer channel is extended into the middle of the main gas channel and kept at a distance of 30-50mm from the front end of the air outlet. The oxygen outer channel extends 20-30mm beyond the butt weld. The air outlet end face is overlaid with a cobalt-based alloy wear-resistant liner. Through the dual optimization of structure and material, the defects of ordinary copper pipe being easily burned due to direct exposure to high combustion temperature are avoided. The combustion heat load is isolated from the air outlet end face from the hardware level, thereby improving the air outlet body's ability to withstand high temperature and resist erosion. (2) This invention maintains the gas flow rate at 220-260 m / s and the oxygen outlet flow rate at 150-180 m / s by precisely controlling the gas flow rate and oxygen outlet flow rate. It relies on the high-speed jet to form a deflaming combustion effect, pushes the high-temperature reaction zone of gas and oxygen to a position in the furnace away from the tuyeres, improves the internal flow field of the tuyeres, suppresses the problem of local heat storage and overheating caused by gas backflow, reduces the thermal erosion of the tuyeres components by high-temperature combustion, takes into account the smelting reaction efficiency of gas, oxygen and coal powder in the HyCROF process, and alleviates the problem of tuyeres burn-out. (3) This invention establishes a standardized operation control process that is fully adapted to the air outlet structure, clarifies the operation logic of each medium under emergency conditions such as start-up, shutdown, and material supply, and pre-introduces no less than 100m³ of gas before supplying it. 3Nitrogen gas is used to protect the oxygen channel, and strict standards are set for the gas flow rate of oxygen injection. In case of abnormal furnace conditions, the operation sequence of reducing oxygen and gas is standardized. If the oxygen flow rate is insufficient, the oxygen supply is forcibly cut off. Nitrogen protection can only be turned off after the high-temperature gas injection has been completely stopped. Relying on feasible operating procedures, the risk of burn-out of the external oxygen channel caused by backfire and backflow of high-temperature media under start-up, shutdown, and abnormal operating conditions is avoided, ensuring the long-term stable operation of the tuyeres, reducing unplanned blast furnace shutdowns, and ensuring the release of blast furnace production capacity.

[0009] Option 2, a preferred option of the basic scheme, involves using copper as the material for the inner oxygen channel and a cobalt-based alloy as the material for the outer oxygen channel. The cobalt-based alloy has a refractory temperature ≥1100℃. Copper has good thermal conductivity, allowing heat from the inner oxygen channel to be removed using a small water-cooling system. The cobalt-based alloy outer oxygen channel has a high refractory temperature and excellent high-temperature resistance, oxidation resistance, and erosion resistance, enabling it to withstand the high-temperature heat load of the gas and oxygen mixing zone. This avoids the problem of ordinary copper pipes easily melting and burning through when directly exposed to the combustion zone, thus extending the service life of the outer oxygen channel.

[0010] Option 3, a preferred option of the basic scheme, involves the injection axis of the outer oxygen channel forming a 0° angle with the injection axis of the main gas channel. The oxygen jet is injected in the same direction and parallel to the high-temperature gas, allowing it to penetrate the main gas flow core at high speed, reducing airflow disturbance and gas backflow, thereby reducing localized vortex heat accumulation within the tuyeres. This facilitates pushing the oxygen and gas combustion reaction zone deeper into the furnace, preventing airflow from impacting the inner wall of the tuyeres and causing localized overheating, thus reducing tuyer erosion.

[0011] Option 4, a preferred option of the basic option, involves a distance of 30-50mm between the end face of the oxygen external channel and the front face of the small sleeve body. This ensures that the oxygen is ejected at a certain depth from the end face of the tuyeres before reacting with the high-temperature coal gas, preventing the oxygen from mixing and burning near the end face of the tuyeres. Structurally, this isolates the high-temperature combustion zone from the front face of the tuyeres, reducing the thermal shock from the high-temperature combustion experienced by the end face of the tuyeres and mitigating burn damage to the end face of the small sleeve.

[0012] Option 5, a control method for the operation of the HyCROF furnace tuyeres, includes: during the operation of the tuyeres, before introducing gas into the main gas channel of the tuyeres, first introducing nitrogen into the oxygen channel, with a nitrogen flow rate ≥100 m³ / h. 3 / h; Next, coal gas is introduced into the main gas channel of the small set. When the coal gas flow rate in the main gas channel of the small set is >220m / s, oxygen is then introduced into the oxygen channel, and the oxygen flow rate at the outlet of the oxygen channel is controlled to be ≥150m / s. This pushes the high-temperature reaction zone of coal gas and oxygen into the furnace, away from the end face of the small set of tuyeres. Nitrogen purging before introducing coal gas into the tuyeres can prevent the backflow of high-temperature coal gas and protect the oxygen channel. Oxygen is only allowed to be introduced after the coal gas flow rate reaches the standard. With the minimum oxygen flow rate, a flameout combustion state is formed, preventing backfire and transferring the high-temperature combustion zone into the furnace, reducing the heat load on the tuyeres.

[0013] Option 6, an optimal choice from Option 5, controls the gas flow rate within the main gas channel of the small unit at 220-260 m / s by controlling the gas injection rate; and controls the oxygen flow rate at the oxygen channel outlet at 150-180 m / s by controlling the oxygen injection rate. The lower limits of gas and oxygen flow rates ensure effective deflaming and prevent backfire and the high-temperature zone from shifting back to the tuyeres; the upper limits prevent excessively high medium flow rates from causing pipeline erosion, excessive energy consumption, and overloading of the injection system. This range of gas and oxygen flow rates balances smelting reaction efficiency with the safety of tuyeres components, while also providing parameter data for on-site control.

[0014] Option 7, a preferred option to Option 5, involves first introducing oxygen into the oxygen channel at a flow rate ≥100 m³ / h when the HyCROF furnace experiences a shutdown, charge failure, or other emergency conditions. 3 To reduce the oxygen supply in the furnace, the nitrogen supply is increased by 100 m / s / h. Simultaneously, the coal gas supply is reduced. When the oxygen flow rate in the oxygen channel is ≤100 m / s, the oxygen supply is cut off, and nitrogen is continuously introduced into the oxygen channel to ensure a nitrogen flow rate ≥100 m / s. 3 / h; When the injection of high-temperature coal gas into the furnace stops, the nitrogen supply is cut off. Nitrogen protection is prioritized under abnormal operating conditions to prevent backfire and damage to the oxygen passages caused by excessively low oxygen flow rate during a reduction in oxygen supply. Strict regulations are established for the criteria for oxygen shutdown and the conditions for continuous nitrogen protection to avoid the risk of tube burnout due to incorrect operation. Nitrogen is only allowed to be shut down after the coal gas injection has completely stopped. This operational procedure avoids oxygen passage burnout in accidental conditions, ensuring equipment safety. Attached Figure Description

[0015] Figure 1 This is a cross-sectional schematic diagram of a small sleeve for a HyCROF furnace tuyeres according to the present invention; Figure 2 This is a left view of a small sleeve for a HyCROF furnace vent according to the present invention; Figure 3 This is a field diagram of burnt-out tuyeres in a small sleeve for a HyCROF furnace according to the present invention; Figure 4 This is a flow field analysis diagram of the burn-off section of the tuyeres in a small sleeve of a HyCROF furnace tuyeres according to the present invention; Figure 5 This is a flow field simulation diagram of a small sleeve for a HyCROF furnace tuyeres according to the present invention; Figure 6 This is a field view of the improved tuyer end face of the HyCROF furnace tuyer sleeve according to the present invention.

[0016] The reference numerals in the accompanying drawings of the instruction manual include: 1. Small sleeve body; 2. Small sleeve main gas channel; 3. Oxygen inner channel; 4. Oxygen outer channel; 5. Small sleeve cooling water channel; 6. Wear-resistant lining; 7. Cooling water inlet; 8. Cooling water outlet; 9. Flow guide. Detailed Implementation

[0017] The present invention will be further described in detail below through specific embodiments: Example 1 like Figure 1 and Figure 2 As shown, a HyCROF furnace tuyeres includes a main body 1, on which a main gas channel 2, an oxygen channel, and a cooling water channel 5 are provided. Wear-resistant linings 6 are provided on the front end face of the main gas channel 1 and along the gas outlet direction of the main gas channel 2. The thickness of the wear-resistant lining 6 is 2-3 mm, and the length of the wear-resistant lining 6 on the main gas channel 2 is 55 mm. A cooling water inlet 7 and a cooling water outlet 8 are provided on the rear end face of the main gas channel 1. The main gas channel 2 is located at the center of the main gas channel 1 and serves as the channel for high-temperature gas to enter the furnace. The oxygen channel includes an internal oxygen channel. The inner oxygen channel 3 and the outer oxygen channel 4 are constructed of copper and cobalt-based alloy. The cobalt-based alloy has a refractory temperature ≥1100℃. The outer oxygen channel 4 is welded to the inner oxygen channel 3 and is inclined and extends into the main gas channel 2 of the small set. The injection axis of the outer oxygen channel 4 forms a 0° angle with the injection axis of the main gas channel 2 of the small set. Oxygen enters the furnace by mixing with the high-temperature and high-speed gas in the main channel through the inner and outer oxygen channels. The distance between the end face of the outer oxygen channel 4 and the front end face of the small set body 1 is 30-50mm. A guide 9 is provided in the cooling water channel 5 of the small set.

[0018] like Figures 3 to 6 As shown, a control method for the operation of a HyCROF furnace tuyer sleeve is provided, based on a HyCROF furnace tuyer sleeve, including: During the operation of the small ventilation system, before introducing coal gas into the main gas channel 2 of the small ventilation system, nitrogen gas should first be introduced into the oxygen channel, with a nitrogen flow rate ≥100 m³ / h. 3 / h; then gas is introduced into the small gas main channel 2, and the gas flow rate in the small gas main channel 2 is controlled at 220-260m / s by controlling the gas injection rate. Then oxygen is introduced into the oxygen channel and the oxygen flow rate at the outlet of the oxygen channel is controlled at 150-180m / s by controlling the oxygen injection rate. By controlling the flow rates of gas and oxygen, the high-temperature reaction zone of high-temperature gas and oxygen is pushed into the HyCROF furnace, thereby moving it away from the tuyeres and reducing the impact of high temperature on the tuyeres. When the HyCROF furnace experiences a shutdown, charge failure, or other emergency, first introduce oxygen into the oxygen channel at a flow rate ≥100 m³ / h. 3 To reduce the oxygen supply in the furnace, the nitrogen supply is increased by 100 m / s / h. Simultaneously, the coal gas supply is reduced. When the oxygen flow rate in the oxygen channel is ≤100 m / s, the oxygen supply is cut off, and nitrogen is continuously introduced into the oxygen channel to ensure a nitrogen flow rate ≥100 m / s. 3 / h; When the injection of high-temperature gas into the furnace is stopped, the nitrogen supply is cut off to prevent the oxygen external channel from burning out.

[0019] In summary, this invention improves the high-temperature resistance and erosion resistance of the tuyeres by employing a dual-channel, graded material structure design for the oxygen supply, an arrangement where the outer oxygen channel extends into the middle of the gas supply channel, and a cobalt-based alloy wear-resistant lining on the end face. By controlling the gas flow rate and oxygen outlet flow rate to achieve deflaming combustion, the high-temperature combustion zones of the gas and oxygen are shifted towards the furnace. Combined with standardized nitrogen purging protection procedures for both commissioning and abnormal shutdown conditions, this effectively solves the problem of burn-off failure caused by the high-temperature zone being close to the end face in traditional tuyeres. Figure 6 As shown above, after the blast furnace shutdown, the end face of the tuyere sleeve is basically undamaged, which ultimately improves the service life of the tuyere sleeve, reduces unplanned blast furnace shutdowns and spare parts wear, ensures the efficient coupling reaction of gas and oxygen in the HyCROF furnace, stably releases blast furnace capacity, and provides structural and technological dual protection for the long-term safe and efficient production of the HyCROF process.

[0020] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A small sleeve for a HyCROF furnace vent, characterized in that, The system includes a small casing body (1), which is provided with a small casing gas main channel (2), an oxygen channel and a small casing cooling water channel (5). The front end face of the small casing body (1) and the small casing gas main channel (2) are provided with wear-resistant lining (6) along the gas outlet direction. The thickness of the wear-resistant lining (6) is 2-3mm. The length of the wear-resistant lining (6) on the small casing gas main channel (2) is 55mm. The rear end face of the small casing body (1) is provided with a cooling water inlet (7) and a cooling water outlet (8). The small casing gas main channel (2) is located at the center of the small casing body (1). The oxygen channel includes an inner oxygen channel (3) and an outer oxygen channel (4). The outer oxygen channel (4) is welded to the inner oxygen channel (3). The outer oxygen channel (4) is inclined and extends into the small casing gas main channel (2). The small casing cooling water channel (5) is provided with a flow guide (9).

2. The small sleeve for the tuyeres of a HyCROF furnace according to claim 1, characterized in that, The oxygen inner channel (3) is made of copper, and the oxygen outer channel (4) is made of cobalt-based alloy material with a fire resistance temperature ≥1100℃.

3. The small sleeve for the tuyeres of a HyCROF furnace according to claim 1, characterized in that, The injection axis of the oxygen external channel (4) forms a 0° angle with the injection axis of the small gas main channel (2).

4. The small sleeve for the tuyeres of a HyCROF furnace according to claim 1, characterized in that, The distance between the end face of the oxygen external channel (4) and the front end face of the small sleeve body (1) is 30-50mm.

5. A control method for the operation of the small sleeve at the tuyeres of a HyCROF furnace, characterized in that, include: During the operation of the small ventilation system, before introducing gas into the main gas channel (2) of the small ventilation system, nitrogen is first introduced into the oxygen channel, with a nitrogen flow rate ≥100m³. 3 / h; then gas is introduced into the main gas channel (2) of the small set. When the gas flow rate of the main gas channel (2) of the small set is >220m / s, oxygen is introduced into the oxygen channel and the oxygen flow rate at the outlet of the oxygen channel is controlled to be ≥150m / s, so that the high temperature zone of the reaction between gas and oxygen is pushed into the furnace and away from the end face of the small set of tuyeres.

6. The control method for the operation of the small sleeve at the tuyeres of a HyCROF furnace according to claim 5, characterized in that, By controlling the amount of coal gas injected, the coal gas flow rate in the main coal gas channel (2) of the small set is controlled at 220-260m / s; by controlling the amount of oxygen injected, the oxygen flow rate at the outlet of the oxygen channel is controlled at 150-180m / s.

7. The control method for the operation of the small sleeve at the tuyeres of a HyCROF furnace according to claim 5, characterized in that, When the HyCROF furnace experiences a shutdown, charge failure, or other emergency, first introduce oxygen into the oxygen channel at a flow rate ≥100 m³ / h. 3 To reduce the oxygen supply in the furnace, the nitrogen supply is increased by 100 m / s / h. Simultaneously, the coal gas supply is reduced. When the oxygen flow rate in the oxygen channel is ≤100 m / s, the oxygen supply is cut off, and nitrogen is continuously introduced into the oxygen channel to ensure a nitrogen flow rate ≥100 m / s. 3 / h; When the injection of high-temperature coal gas into the furnace stops, the nitrogen supply is cut off.

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