Material high-temperature hydrogen permeation simulation experiment device and method based on reverse diffusion flame burner

Abstract

The invention discloses a material high-temperature hydrogen permeation simulation experiment device and method based on a reverse diffusion flame burner, fuel enters a fuel cavity with horizontal initial momentum and is discharged after the initial momentum is weakened, and an oxidant is vertically discharged at an initial speed and is distributed above fuel airflow, so that a speed difference is formed between the fuel and the oxidant; the oxidant can form an entrainment effect on fuel so as to promote mixing of the oxidant and the fuel, improve stability and heat release efficiency of reverse diffusion flames and ensure sufficient combustion and flame temperature distribution uniformity, meanwhile, efficient and uniform mixing can be achieved without a rotational flow generator, the structure of the reverse diffusion flame burner is simplified, and the cost is reduced. The data acquisition and control system can adjust the equivalence ratio of the oxidant to the fuel so as to adjust the combustion state of the flame, so that the flame height, the temperature and the active free radical concentration are accurately controlled, the application scene of the sample is effectively simulated, various flame environments can be provided for the performance experiment of the sample, and the experiment reliability is improved.

Description

Technical Field

[0001] This invention relates to the field of material performance testing technology, specifically to a high-temperature hydrogen permeation simulation experimental device for materials based on a reverse diffusion flame burner. Background Technology

[0002] With the rapid development of the hydrogen energy industry (such as hydrogen fuel cells, hydrogen storage tanks, and hydrogen pipelines), the long-term safety and reliability of key component materials under high pressure and high temperature hydrogen environments face severe challenges. Hydrogen embrittlement, as one of the main failure modes, refers to the phenomenon that metallic materials undergo delayed fracture under static stress due to a significant decrease in plasticity and toughness caused by hydrogen absorption.

[0003] Currently, commonly used hydrogen permeation testing methods include electrochemical hydrogen charging and high-pressure hydrogen chamber static exposure. Electrochemical hydrogen charging introduces hydrogen atoms by charging the cathode with hydrogen in an electrolyte solution before mechanical testing, but it cannot simulate a real high-temperature gaseous hydrogen environment. High-pressure hydrogen chamber testing involves exposing the material to a high-pressure hydrogen tank at a constant temperature, which is closer to some operating conditions, but it suffers from long testing cycles, complex equipment, and high safety risks. Furthermore, its static, heat-free testing method makes it difficult to reproduce the actual scenario of high-temperature thermal cycling coupled with a dynamic hydrogen atmosphere.

[0004] Furthermore, reverse diffusion flame refers to a combustion form where a fuel jet surrounds an oxidizer jet. Compared to conventional diffusion flames, reverse diffusion flames offer advantages such as more thorough mixing, higher heat release efficiency, and cleaner combustion. Existing reverse diffusion flame burners mostly employ a coaxial annular structure, with the oxidizer flowing through the inner layer and the fuel through the outer layer, and often utilize swirling structures to enhance mixing. For example, Chinese Patent No. CN 208764920 U discloses a swirling reverse diffusion flame burner, which features a dedicated swirling generation chamber, allowing fuel to enter tangentially to form a swirling flow. However, existing reverse diffusion flame burners are complex, costly to manufacture, and their generated flame flow field, temperature, and concentration distribution cannot accurately simulate the high-temperature hydrogen environment of materials, making them unsuitable for effective high-temperature hydrogen permeation experiments.

[0005] Therefore, providing an experimental device with a simple structure that can safely and realistically simulate a high-temperature hydrogen environment and achieve efficient and reliable hydrogen permeation testing of materials has become an urgent problem to be solved in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a simple, effective, safe, and reliable experimental apparatus and method for simulating high-temperature hydrogen permeation of materials based on a reverse diffusion flame burner.

[0007] To achieve the above objectives, the present invention provides a high-temperature hydrogen permeation simulation experimental device for materials based on a reverse diffusion flame burner, comprising a reverse diffusion flame burner, a gas supply system, a sample fixation system, and a data acquisition and control system. The reverse diffusion flame burner has an oxidant transition chamber and a fuel chamber inside. The oxidant transition chamber is located in the bottom area of ​​the reverse diffusion flame burner and is connected to the oxidant inlet pipe. The fuel chamber is located in the top area of ​​the reverse diffusion flame burner and is connected to the fuel inlet pipe. The top of the fuel chamber is open to form a fuel exhaust port. The fuel chamber is also provided with an oxidant exhaust pipe assembly. One end of the oxidant exhaust pipe assembly is connected to the oxidant transition chamber, and the other end extends out of the fuel chamber and is higher than the fuel exhaust port. The fuel in the fuel intake pipe enters the fuel chamber with horizontal initial momentum and forms a momentum weakening state in the fuel chamber before being discharged from the fuel exhaust port. The oxidant in the oxidant intake pipe enters the oxidant transition chamber and forms a steady flow state in the oxidant transition chamber before being discharged vertically along the oxidant exhaust pipe assembly with an initial velocity and distributed above the fuel flow, forming a velocity difference with the fuel and entraining the fuel. The gas supply system is connected to the oxidant inlet pipe and the fuel inlet pipe respectively, and can deliver oxidant and fuel to the reverse diffusion flame burner; The sample fixing system is distributed above the reverse diffusion flame burner and is used to clamp and move the sample, immersing the sample in different areas of the flame for the experiment. The data acquisition and control system can control the working state of the gas supply system, adjust the equivalence ratio of oxidant and fuel to adjust the flame state generated by the reverse diffusion flame burner, and can also monitor the surface temperature and hydrogen concentration of the sample in real time.

[0008] Furthermore, the oxidant inlet pipe and the fuel inlet pipe are horizontally distributed and connected to the oxidant transition chamber and the fuel chamber, respectively.

[0009] Furthermore, the oxidant exhaust pipe assembly includes a central exhaust pipe and peripheral exhaust pipes. The central exhaust pipe is located in the central region of the fuel chamber, and several peripheral exhaust pipes are equidistantly surrounding the central exhaust pipe, forming an X-shaped distribution.

[0010] Furthermore, the gas supply system includes a high-pressure air cylinder and a high-pressure hydrogen cylinder. The high-pressure air cylinder is connected to the oxidant inlet pipe via a gas control valve and a gas mass flow controller, and the high-pressure hydrogen cylinder is connected to the fuel inlet pipe via a gas control valve and a gas mass flow controller.

[0011] Furthermore, the data acquisition and control system is connected to the gas control valve and the gas mass flow controller, and the data acquisition and control system also includes thermocouples and hydrogen sensors distributed above the reverse diffusion flame burner.

[0012] Furthermore, the sample fixing system includes an X-axis moving mechanism, a Y-axis moving mechanism, and a Z-axis moving mechanism. The Z-axis moving mechanism can move along the height direction of the sample fixing system. The X-axis moving mechanism is slidably disposed on the Z-axis moving mechanism and can move axially along the Z-axis moving mechanism. The Y-axis moving mechanism is slidably disposed on the X-axis moving mechanism and can move radially along the X-axis moving mechanism.

[0013] Furthermore, the Y-axis moving mechanism is provided with a sample fixing mechanism and a sensor extension mounting slot.

[0014] Furthermore, the reverse diffusion flame burner also includes a protective gas inlet pipe, which can form a protective gas curtain around the port of the reverse diffusion flame burner.

[0015] To achieve the above objectives, the present invention provides a high-temperature hydrogen permeation simulation experimental method for materials based on a reverse diffusion flame burner, the experimental method comprising: Preliminary experiments were conducted by controlling the working state of the gas supply system and adjusting the equivalence ratio of oxidant and fuel to determine the flame state of the experiment. In the formal experiment, the sample clamping system holds the sample and moves it above the reverse diffusion flame burner, corresponding to the experimental area of ​​the flame. When the reverse diffusion flame burner is ignited, the fuel in the fuel intake pipe enters the fuel chamber with initial horizontal momentum, forming a momentum-weakened state within the fuel chamber, and then exits from the fuel exhaust port. The oxidizer in the oxidizer intake pipe enters the oxidizer transition chamber, forming a steady flow state within the oxidizer transition chamber, and then exits vertically along the oxidizer exhaust pipe assembly with an initial velocity, distributing above the fuel flow and entraining the fuel. Meanwhile, the sample is immersed in the experimental area of ​​the flame. The data acquisition and control system monitors the surface temperature and hydrogen concentration of the sample in real time and adjusts the working state of the gas supply system to maintain the flame state. After the formal experiment is completed, the flame is extinguished and excess fuel is discharged through the fuel exhaust port.

[0016] The present invention provides a high-temperature hydrogen permeation simulation experimental device and method based on a reverse diffusion flame burner. Fuel enters the fuel chamber with horizontal initial momentum, weakens the horizontal initial momentum, and is then discharged. Oxidant is discharged vertically with initial velocity and distributed above the fuel gas flow, so that a velocity difference is formed between fuel and oxidant. The oxidant can entrain the fuel to promote the mixing of oxidant and fuel, improve the stability and heat release efficiency of the reverse diffusion flame, ensure complete combustion and uniform flame temperature distribution, and achieve efficient and uniform mixing without the need for a swirl generator, thus simplifying the structure of the reverse diffusion flame burner.

[0017] Furthermore, the fuel chamber has an open top to form a fuel exhaust port, allowing excess fuel that has not burned or participated in the reaction to diffuse into the atmosphere, preventing fuel from accumulating inside the reverse diffusion flame burner and improving experimental safety.

[0018] Furthermore, the data acquisition and control system can adjust the stoichiometric ratio of oxidant and fuel to regulate the combustion state of the flame, thereby precisely controlling the flame height, temperature, and concentration of active free radicals. This effectively simulates the application scenarios of the sample and provides various flame environments for the performance experiments of the sample, improving experimental reliability. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0020] Figure 1 System block diagram of the high-temperature hydrogen permeation simulation experimental device for materials based on a reverse diffusion flame burner provided by the present invention; Figure 2 A schematic diagram of the overall structure of the high-temperature hydrogen permeation simulation experimental device for materials based on a reverse diffusion flame burner provided by the present invention; Figure 3 This is a schematic diagram of the overall structure of the reverse diffusion flame burner in this invention; Figure 4 This is a top view schematic diagram of the reverse diffusion flame burner in this invention; Figure 5 This is a cross-sectional view of the reverse diffusion flame burner in this invention; Figure 6 This is a schematic diagram of the sample fixing system in this invention; Figure 7 This is a schematic diagram of the flame height curves under different equivalence ratios of oxidizer and fuel in this invention; Figure 8 This is a schematic diagram showing the flame height under different equivalence ratios when the fuel flow rate is 3 SLM in this invention; Figure 9 This is a schematic diagram of the mixing boundary of oxidant and fuel under different fuel flow rates when the equivalence ratio of oxidant to fuel is 1 in this invention.

[0021] Figure label: 1. Reverse diffusion flame burner; 11. Base; 12. Burner body; 13. Oxidizer inlet pipe; 14. Fuel inlet pipe; 15. Oxidizer transition chamber; 16. Fuel chamber; 17. Fuel exhaust port; 18. Oxidizer exhaust pipe assembly; 181. Central exhaust pipe; 182. Peripheral exhaust pipe; 2. Gas supply system; 21. High-pressure air cylinder; 22. High-pressure hydrogen cylinder; 23. Gas control valve; 24. Gas mass flow controller; 3. Sample fixing system; 31. Fixing frame; 32. X-axis moving mechanism; 33. Y-axis moving mechanism; 34. Z-axis moving mechanism; 35. Sample fixing mechanism; 36. Sensor extension mounting slot; 4. Data acquisition and control system; 41. Thermocouple; 42. Hydrogen sensor. Detailed Implementation

[0022] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific illustrations.

[0023] See Figure 1 and Figure 2 The image shows an example of a high-temperature hydrogen permeation simulation experimental device for materials based on a reverse diffusion flame burner provided by the present invention.

[0024] Depend on Figure 1 and Figure 2 As can be seen, the high-temperature hydrogen permeation simulation experimental device based on the reverse diffusion flame burner in this example mainly includes a reverse diffusion flame burner 1, a gas supply system 2, a sample fixing system 3, and a data acquisition and control system 4.

[0025] The reverse diffusion flame burner 1 allows fuel to enter with horizontal initial momentum, weakens the horizontal initial momentum, and then exits. The oxidant is discharged vertically with an initial velocity and distributed above the fuel gas flow, creating a velocity difference between the fuel and the oxidant. The oxidant can entrain the fuel, promoting the mixing of the oxidant and the fuel, improving the stability and heat release efficiency of the reverse diffusion flame, ensuring complete combustion and uniform flame temperature distribution. At the same time, it can achieve efficient and uniform mixing without the need for a swirl generator, simplifying the structure of the reverse diffusion flame burner.

[0026] Furthermore, the gas supply system 2 can deliver oxidant and fuel to the reverse diffusion flame burner 1; the sample fixing system 3 is distributed above the reverse diffusion flame burner 1 and is used to clamp and move the sample, immersing the sample in different areas of the flame for the experiment; the data acquisition and control system 4 can control the working state of the gas supply system 2, adjust the equivalence ratio of oxidant and fuel to adjust the flame state generated by the reverse diffusion flame burner 1, and can also monitor the surface temperature and hydrogen concentration of the sample in real time to improve the safety and reliability of the experiment.

[0027] Combination Figures 3 to 5 Specifically, the reverse diffusion flame burner 1 includes a base 11, a burner body 12, an oxidizer inlet pipe 13 and a fuel inlet pipe 14. The burner body 12 is mounted on the base 11, and an oxidizer transition chamber 15 and a fuel chamber 16 are also formed inside the burner body 12.

[0028] The oxidant transition chamber 15 is located in the bottom area of ​​the burner body 12 and is connected to the oxidant inlet pipe 13. Oxidant is supplied to the oxidant transition chamber 15 through the oxidant inlet pipe 13. The fuel chamber 16 is located in the top area of ​​the burner body 12 and is connected to the fuel inlet pipe 14. Fuel is supplied to the fuel chamber 16 through the fuel inlet pipe 14.

[0029] Furthermore, the oxidant inlet pipe 13 and the fuel inlet pipe 14 are horizontally distributed and connected to the oxidant transition chamber 15 and the fuel chamber 16, respectively, so that the oxidant and fuel are horizontally transported to the oxidant transition chamber 15 and the fuel chamber 16, respectively.

[0030] Furthermore, the top of the fuel chamber 16 is completely open to form a fuel exhaust port 17. The fuel chamber 16 is also provided with an oxidant exhaust pipe assembly 18. One end of the oxidant exhaust pipe assembly 18 is connected to the oxidant transition chamber 15, and the other end extends out of the top of the fuel chamber 16 and is higher than the fuel exhaust port 17, so that the fuel in the fuel chamber 16 diffuses and is discharged through the fuel exhaust port 17, and the oxidant in the oxidant transition chamber 15 is discharged vertically along the oxidant exhaust pipe assembly 18 and distributed above the fuel flow.

[0031] Combination Figure 5 Therefore, the fuel in the fuel intake pipe 14 enters the fuel chamber 16 with horizontal initial momentum. The fuel is subject to air resistance in the semi-open fuel chamber 16 and collides with the inner wall of the fuel chamber 16. Under the combined action of air resistance and collision force, the horizontal initial momentum of the fuel is rapidly weakened, forming a momentum weakened state in the fuel chamber 16. Based on the fuel's own gravity, it moves and diffuses at a low speed in the fuel chamber 16 toward the fuel exhaust port 17, and is finally discharged from the fuel exhaust port 17, forming a low-speed diffused fuel flow around the fuel exhaust port 17.

[0032] Simultaneously, the oxidant in the oxidant intake pipe 13 enters the oxidant transition chamber 15 horizontally. The outlet of the oxidant in the oxidant transition chamber 15 is restricted and cannot be discharged quickly, thus accumulating in the oxidant transition chamber 15 to form a stable pressure field, so that the oxidant forms a steady flow state in the oxidant transition chamber 15, and is then discharged vertically along the oxidant exhaust pipe assembly 18 to form a concentrated, high-speed oxidant airflow.

[0033] Since the oxidizer exhaust pipe assembly 18 extends beyond the top of the fuel chamber 16 and is higher than the fuel exhaust port 17, the high-speed oxidizer airflow is distributed above the low-speed fuel airflow, creating a velocity difference between the oxidizer and the fuel. The oxidizer with a higher flow rate will generate a lower pressure, causing the fuel to move towards the oxidizer. This results in the oxidizer entraining the fuel, achieving a thorough mixing of the oxidizer and the fuel, improving the stability and heat release efficiency of the reverse diffusion flame, and ensuring complete combustion and uniform flame temperature distribution.

[0034] Meanwhile, the oxidant and fuel form a "top-down" entrainment mixing method, which can achieve efficient and uniform mixing without the need for a complex swirl generator, thus simplifying the structure of the reverse diffusion flame burner 1.

[0035] Combination Figures 3 to 5 To further improve the uniformity of flame combustion, the oxidizer exhaust pipe assembly 18 includes a central exhaust pipe 181 and a peripheral exhaust pipe 182 with the same diameter and length, so that the flow rate and velocity of the oxidizer discharged from the central exhaust pipe 181 and the peripheral exhaust pipe 182 are consistent.

[0036] Furthermore, the central exhaust pipe 181 is located in the middle region of the fuel chamber 16, and several peripheral exhaust pipes 182 are equidistantly surrounding the central exhaust pipe 181. The peripheral exhaust pipes 182 together form an X-shaped distribution to ensure the symmetry and uniformity of the oxidant gas outlet flow field, making the flame shape more stable and uniform, and providing a uniform high-temperature hydrogen environment for the sample to improve the reliability of the experiment.

[0037] Furthermore, during the combustion of the oxidizer and fuel, excess fuel that is not burned or does not participate in the reaction can be diffused into the atmosphere in a timely manner through the fuel exhaust port 17 at the top of the fuel chamber 16, preventing fuel from accumulating inside the reverse diffusion flame burner 1 and improving experimental safety.

[0038] In some embodiments, the reverse diffusion flame burner 1 further includes a protective gas inlet pipe, which is disposed around the fuel exhaust port 17 and can deliver inert protective gas (such as nitrogen or argon) to form a protective gas curtain around the port of the reverse diffusion flame burner 1. This effectively isolates the interference of ambient air, ensures pure flame combustion, and allows for rapid purging with inert protective gas after the experiment to extinguish the flame and protect the high-temperature sample, preventing oxidation of the sample upon contact with air. This provides assurance for subsequent experimental analysis and ensures experimental safety and reliability.

[0039] The reverse diffusion flame burner 1 thus constitutes an oxidant that entrains the fuel, ensuring that the oxidant and fuel are fully mixed, thereby providing a uniform and stable high-temperature hydrogen environment for the sample.

[0040] Combination Figure 2 Furthermore, the gas supply system 2 is connected to the oxidant inlet pipe 13 and the fuel inlet pipe 14 of the reverse diffusion flame burner 1, and can stably supply oxidant and fuel to the reverse diffusion flame burner 1.

[0041] Specifically, the gas supply system 2 includes a high-pressure air cylinder 21 and a high-pressure hydrogen cylinder 22. The high-pressure air cylinder 21 and the high-pressure hydrogen cylinder 22 are respectively connected to the oxidant inlet pipe 13 and the fuel inlet pipe 14. A gas control valve 23 and a gas mass flow controller 24 are provided on the connecting pipes to supply air and hydrogen to the oxidant inlet pipe 13 and the fuel inlet pipe 14, so that the flame generated by the reverse diffusion flame burner 1 forms a high-temperature hydrogen environment.

[0042] In conjunction with this, the data acquisition and control system 4 is connected to the gas control valve 23 and the gas mass flow controller 24, which can control the working state of the gas control valve 23 to respectively shut off the connection pipelines between the high-pressure air cylinder 21 and the high-pressure hydrogen cylinder 22 and the oxidant inlet pipe 13 and the fuel inlet pipe 14, start and stop the supply of oxidant and fuel, thereby controlling the combustion and extinguishing of the flame in the reverse diffusion flame burner 1.

[0043] Furthermore, the data acquisition and control system 4 can also control the working state of the gas mass flow controller 24 to adjust the delivery flow of oxidant and fuel respectively. By adjusting the equivalence ratio (flow ratio) of oxidant and fuel, the flame combustion state can be changed, thereby precisely controlling the position, temperature distribution, and types and concentrations of active free radicals generated in the flame. This allows for the simulation of high-temperature hydrogen environments with different chemical activities and application scenarios of the sample, and provides multiple flame environments for the performance experiments of the sample, improving experimental reliability.

[0044] Combination Figure 2 and Figure 6 The experimental apparatus also includes a sample fixing system 3, which is located above the reverse diffusion flame burner 1 and is used to hold and move the sample. According to the experimental requirements, the sample is immersed in different regions of the flame (such as the flame core, reducing flame or oxidizing flame region) for the experiment.

[0045] Specifically, the sample fixing system 3 includes a fixed mounting frame 31, which is suspended or fixed above the reverse diffusion flame burner 1. The fixed mounting frame 31 is provided with an X-axis moving mechanism 32, a Y-axis moving mechanism 33 and a Z-axis moving mechanism 34, so that the X-axis moving mechanism 32, the Y-axis moving mechanism 33 and the Z-axis moving mechanism 34 cooperate to form a three-dimensional moving platform, which can drive the sample to move freely and ensure that the sample can be accurately immersed in the flame.

[0046] The Z-axis moving mechanism 34 is slidably mounted in the vertical slide rail of the fixed mounting frame 31 and can move along the height direction of the fixed mounting frame 31. The Z-axis moving mechanism 34 is provided with an axial slide rail. The X-axis moving mechanism 32 is sleeved on the Z-axis moving mechanism 34 and is slidably connected to the axial slide rail of the Z-axis moving mechanism 34 and can move axially along the Z-axis moving mechanism 34. The bottom end of the X-axis moving mechanism 32 is also provided with a radial slide rail. The Y-axis moving mechanism 33 is slidably mounted on the radial slide rail and can move radially along the X-axis moving mechanism 32.

[0047] Furthermore, the Y-axis moving mechanism 33 is provided with a sample fixing mechanism 35, which can be made of a high-temperature resistant ceramic or metal clamp to stably clamp the sample. This allows the three-dimensional moving platform formed by the X-axis moving mechanism 32, the Y-axis moving mechanism 33, and the Z-axis moving mechanism 34 to stably drive the sample to move freely, ensuring that the sample is accurately immersed in the flame. Depending on the experimental requirements, the sample can be immersed in different areas of the flame (such as the flame core, reducing flame, or oxidizing flame area) for the experiment.

[0048] In some embodiments, the Y-axis moving mechanism 33 is further provided with a sensor extension mounting slot 36, which is close to the sample fixing mechanism 35 and is used to install temperature sensors, hydrogen concentration sensors, etc., to monitor the experimental status of the sample in the flame in real time.

[0049] The sample fixing system 3 thus constitutes a stable clamping and moving system, ensuring stable cooperation between the sample and the high-temperature hydrogen environment provided by the reverse diffusion flame burner 1, thereby improving experimental reliability.

[0050] Combination Figure 2 In conjunction with this, the data acquisition and control system 4 also includes thermocouples 41 and hydrogen sensors 42 distributed above the reverse diffusion flame burner 1. In this example, thermocouples 41 and hydrogen sensors 42 are close to the sample and distributed on both sides of the sample to monitor the surface temperature and hydrogen concentration of the sample immersed in the flame in real time. Based on this, the gas mass flow controllers 24 on the high-pressure air cylinder 21 and the high-pressure hydrogen cylinder 22 are adjusted in real time to adjust the equivalence ratio of oxidant and fuel to ensure that the flame state remains stable.

[0051] This constitutes the high-temperature hydrogen permeation simulation experimental device for materials based on a reverse diffusion flame burner provided by the present invention.

[0052] This invention also provides a method for simulating high-temperature hydrogen permeation of materials based on a reverse diffusion flame burner. Based on the aforementioned experimental apparatus, this method includes: First, a pre-experiment check is performed. The data acquisition and control system 4 opens the gas control valves 23 on the high-pressure air cylinder 21 and the high-pressure hydrogen cylinder 22 to ensure the airtightness of the connection between the reverse diffusion flame burner 1 and the gas supply system 2.

[0053] Next, a preliminary experiment was conducted. The data acquisition and control system 4 adjusted the gas mass flow controller 24 on the high-pressure air cylinder 21 and the high-pressure hydrogen cylinder 22 to adjust the equivalence ratio of oxidant and fuel, determine the flame state and duration required for the experiment, and set the preset flow rates of oxidant and fuel.

[0054] Further, in the formal experiment, the sample fixing system 3 clamps the sample and moves the sample through the cooperation of the X-axis moving mechanism 32, the Y-axis moving mechanism 33 and the Z-axis moving mechanism 34 to ensure that the sample can be accurately immersed in the experimental area of ​​the flame.

[0055] Next, the reverse diffusion flame burner 1 is ignited. For safety reasons, the ignition source is placed close to the oxidant exhaust pipe assembly 18. The data acquisition and control system 4 first controls the gas mass flow controller 24 of the high-pressure hydrogen cylinder 22 to ensure that the hydrogen flow reaches the preset value. After hearing a "bang" sound and observing the flame, the ignition source is removed, and then the gas mass flow controller 24 of the high-pressure air cylinder 21 is controlled to adjust the oxidant flow to the preset value.

[0056] Therefore, the fuel in the fuel inlet pipe 14 enters the fuel chamber 16 of the reverse diffusion flame burner 1 with horizontal initial momentum, and forms a momentum weakening state in the fuel chamber 16. It is then discharged from the fuel exhaust port 17 at a low speed. The oxidant in the oxidant inlet pipe 13 enters the oxidant transition chamber 15, and forms a steady flow state in the oxidant transition chamber 15. It is then discharged vertically along the oxidant exhaust pipe assembly 18 at an initial speed and distributed above the fuel flow, forming a fuel entrainment to ensure complete combustion and uniform flame temperature distribution.

[0057] Meanwhile, the sample is immersed in the experimental area of ​​the flame. The data acquisition and control system 4 monitors the surface temperature and hydrogen concentration of the sample in real time, and adjusts the gas mass flow controller 24 on the high-pressure air cylinder 21 and the high-pressure hydrogen cylinder 22 in real time to adjust the equivalence ratio of oxidant and fuel to ensure that the flame state remains stable.

[0058] After the formal experiment is completed, the high-temperature sample is cooled and stored in an inert atmosphere protection box. The data acquisition and control system 4 closes the gas control valve 23 on the high-pressure air cylinder 21 and the high-pressure hydrogen cylinder 22, extinguishes the flame, and the excess fuel is discharged through the fuel exhaust port 17.

[0059] The following examples illustrate the working process of this invention in a specific application. It should be noted that the content described here is only a specific application example of this solution and does not constitute a limitation on this solution.

[0060] Taking the distance between the oxidizer exhaust pipe assembly 18 and the fuel exhaust port 17 as 1 cm as an example, the vertical velocity of the fuel when it reaches the top of the oxidizer exhaust pipe assembly 18 can be calculated by combining Archimedes' law of buoyancy and Newton's second law. The calculation formula is: ; In the formula, Density of air (oxidant); The density of the fuel (hydrogen); It is the acceleration due to gravity; is the vertical velocity of the fuel when it reaches the top of the oxidizer exhaust pipe assembly 18; s is the distance the fuel travels when it reaches the top of the oxidizer exhaust pipe assembly 18.

[0061] In this example, using hydrogen as fuel, calculations show that under ideal conditions where air resistance is negligible... However, the fuel in the fuel chamber 16 will be affected by air resistance, so the vertical velocity of the fuel will be... Within the range, the speed is much smaller than that under ideal conditions, so the initial horizontal momentum of the fuel is weakened, and after forming a momentum-weakened state in the fuel cavity 16, it moves and diffuses towards the fuel exhaust port 17.

[0062] In this example, air is used as the oxidant, and the air flow rate is... At that time, calculations show that the vertical velocity of air discharged from the oxidizer exhaust pipe assembly 18 at normal temperature and pressure is approximately At this point, a significant velocity difference has been formed between the air and the fuel. As the airflow increases, the velocity difference between the air and the fuel increases linearly, which allows the oxidant to effectively entrain the fuel, thereby achieving full mixing of the oxidant and the fuel and improving flame uniformity.

[0063] Furthermore, the data acquisition and control system 4 adjusts the gas mass flow controller 24 on the high-pressure air cylinder 21 and the high-pressure hydrogen cylinder 22 to adjust the equivalence ratio of oxidant and fuel, thereby adjusting the flame state. See [link to relevant documentation]. Figure 7 The figure shows the flame height curves under different stoichiometric ratios of oxidizer and fuel. This represents the equivalence ratio of oxidizer to fuel, indicating the actual fuel-to-oxidizer ratio. The air consumption coefficient is the ratio of the actual fuel to oxidant to the theoretical chemical ratio. The air consumption coefficient varies for different equivalence ratios.

[0064] At the same equivalence ratio, the higher the gas flow rate (SLM) of the oxidizer and fuel, the higher the flame height (e.g., the flame height of 4 SLM is always much higher than that of 1 SLM), while at the same gas flow rate, the flame height generally decreases as the equivalence ratio decreases.

[0065] See Figure 8 Q H2 Indicates the flow rate of fuel (hydrogen). This represents the ratio of the actual fuel to oxidizer ratio (equivalent ratio) to the theoretical chemical ratio, i.e., the air consumption coefficient. The air consumption coefficient varies for different equivalent ratios. The figure shows the flame height at different equivalent ratios when the fuel (hydrogen) flow rate is 3 SLM. Figure 8 As shown, when the fuel flow rate is 3 SLM, the flame height decreases as the equivalence ratio decreases.

[0066] Therefore, the data acquisition and control system 4 can adjust the delivery flow rate of oxidant and fuel. By adjusting the equivalence ratio of oxidant and fuel, it can change the flame combustion state to simulate different high-temperature hydrogen environments and application scenarios of the sample, and provide multiple flame environments for the performance test of the sample, thereby improving the reliability of the experiment.

[0067] Further, see Figure 9 The figure shows the mixing boundary of oxidant and fuel at different fuel (hydrogen) flow rates when the equivalence ratio of oxidant to fuel is 1. molef-h2 represents the mole fraction of fuel (hydrogen). Figure 9 As shown, h is the fully mixed region of oxidant and fuel. Below h, oxidant and fuel are not fully mixed. When the fuel (hydrogen) flow rate is 1L / min, the height of the fully mixed region of oxidant and fuel is up to 1.312cm. Therefore, the reverse diffusion flame burner 1 can achieve the entrainment effect of oxidant on fuel, promote the full mixing of oxidant and fuel, and thus ensure complete combustion and uniform flame temperature distribution.

[0068] The present invention provides a high-temperature hydrogen permeation simulation experimental device and method based on a reverse diffusion flame burner. Fuel enters the reverse diffusion flame burner 1 with horizontal initial momentum, and is discharged after the horizontal initial momentum is weakened. Oxidant is discharged vertically with initial velocity and distributed above the fuel gas flow, so that the fuel and oxidant form a velocity. The oxidant can form an entrainment effect on the fuel to promote the mixing of oxidant and fuel, improve the stability and heat release efficiency of the reverse diffusion flame, ensure complete combustion and uniform flame temperature distribution, and achieve efficient and uniform mixing without the need for a swirl generator, thus simplifying the structure of the reverse diffusion flame burner 1.

[0069] Furthermore, the data acquisition and control system 4 can adjust the equivalence ratio of oxidant and fuel to regulate the combustion state of the flame, thereby precisely controlling the flame height, temperature and active free radical concentration, effectively simulating the application scenario of the sample, and providing a variety of flame environments for the performance test of the sample, thus improving the reliability of the experiment.

[0070] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A material high-temperature hydrogen permeation simulation experimental device based on a counter-diffusion flame burner, characterized in that, The device comprises a counterflow diffusion flame burner, a gas supply system, a sample fixing system and a data acquisition and control system, The counterflow diffusion flame burner is internally formed with an oxidant transition cavity and a fuel cavity, the oxidant transition cavity is distributed in the bottom area of the counterflow diffusion flame burner and is connected with an oxidant inlet pipe, the fuel cavity is distributed in the top area of the counterflow diffusion flame burner and is connected with a fuel inlet pipe, the top end of the fuel cavity is open to form a fuel exhaust port, and an oxidant exhaust pipe assembly is further arranged in the fuel cavity, one end of the oxidant exhaust pipe assembly is communicated with the oxidant transition cavity, and the other end extends out of the fuel cavity and is higher than the fuel exhaust port; The fuel in the fuel inlet pipe enters the fuel cavity with horizontal initial momentum, forms a momentum weakening state in the fuel cavity, and is discharged from the fuel exhaust port, the oxidant in the oxidant inlet pipe enters the oxidant transition cavity and forms a steady flow state in the oxidant transition cavity, is vertically discharged along the oxidant exhaust pipe assembly at an initial speed, and is distributed above the fuel gas flow to form a speed difference with the fuel and to form entrainment to the fuel; The gas supply system is connected with the oxidant inlet pipe and the fuel inlet pipe respectively, and can deliver oxidant and fuel to the counterflow diffusion flame burner; The sample fixing system is distributed above the counterflow diffusion flame burner, and is used to clamp and move the sample to immerse the sample in different areas of the flame for experiment; The data acquisition and control system can control the working state of the gas supply system, adjust the equivalence ratio of the oxidant and the fuel, adjust the flame state generated by the counterflow diffusion flame burner, and can also monitor the surface temperature and hydrogen concentration of the sample in real time.

2. The material high temperature hydrogen permeation simulation experimental apparatus based on inverse diffusion flame burner according to claim 1, characterized in that, The oxidant inlet pipe and the fuel inlet pipe are horizontally distributed and connected with the oxidant transition cavity and the fuel cavity respectively.

3. The material high temperature hydrogen permeation simulation experimental apparatus based on inverse diffusion flame burner according to claim 1, characterized in that, The oxidant exhaust pipe assembly comprises a central exhaust pipe and peripheral exhaust pipes, the central exhaust pipe is arranged in the middle area of the fuel cavity, and a plurality of peripheral exhaust pipes are equidistantly arranged around the central exhaust pipe to form an X-shaped distribution.

4. The material high temperature hydrogen permeation simulation experimental apparatus based on inverse diffusion flame burner according to claim 1, characterized in that, The gas supply system comprises a high-pressure air bottle and a high-pressure hydrogen bottle, the high-pressure air bottle is connected with the oxidant inlet pipe through a gas control valve and a gas mass flow controller, and the high-pressure hydrogen bottle is connected with the fuel inlet pipe through a gas control valve and a gas mass flow controller.

5. The material high temperature hydrogen permeation simulation experimental apparatus based on inverse diffusion flame burner according to claim 4, characterized in that, The data acquisition and control system is connected with the gas control valve and the gas mass flow controller, and further comprises a thermocouple and a hydrogen sensor distributed above the counterflow diffusion flame burner.

6. The inverse diffusion flame burner based material high temperature hydrogen permeation simulation experimental apparatus according to claim 1, characterized in that, The sample fixing system comprises an X-axis moving mechanism, a Y-axis moving mechanism and a Z-axis moving mechanism, the Z-axis moving mechanism can move along the height direction of the sample fixing system, the X-axis moving mechanism is slidingly arranged on the Z-axis moving mechanism and can move axially along the Z-axis moving mechanism, and the Y-axis moving mechanism is slidingly arranged on the X-axis moving mechanism and can move radially along the X-axis moving mechanism.

7. The material high temperature hydrogen permeation simulation experimental apparatus based on inverse diffusion flame burner according to claim 6, characterized in that, The Y-axis moving mechanism is provided with a sample fixing mechanism and a sensor expansion mounting groove.

8. The inverse diffusion flame burner based material high temperature hydrogen permeation simulation experimental apparatus according to claim 1, characterized in that, The reverse diffusion flame burner further comprises a protective gas inlet pipe capable of forming a protective gas curtain outside the periphery of the reverse diffusion flame burner port.

9. The experimental method of the material high temperature hydrogen permeation simulation experimental apparatus based on inverse diffusion flame burner according to any one of claims 1-8, characterized in that, The experimental method comprises: Pre-experiment, the data acquisition and control system controls the working state of the gas supply system, adjusts the equivalence ratio of the oxidant and the fuel to carry out pre-experiment, so as to determine the flame state of the experiment; Formal experiment, the sample fixing system clamps the sample and moves the sample to above the reverse diffusion flame burner, corresponding to the experimental area of the flame; Ignite the reverse diffusion flame burner, the fuel in the fuel inlet pipe enters the fuel cavity with horizontal initial momentum, forms a momentum weakening state in the fuel cavity, and is discharged from the fuel exhaust port, the oxidant in the oxidant inlet pipe enters the oxidant transition cavity, forms a steady flow state in the oxidant transition cavity, is vertically discharged along the oxidant exhaust pipe assembly at an initial speed, and is distributed above the fuel gas flow to form entrainment to the fuel, At the same time, the sample is immersed in the experimental area of the flame, the data acquisition and control system monitors the surface temperature and hydrogen concentration of the sample in real time, adjusts the working state of the gas supply system to maintain the flame state, and after the formal experiment is completed, the flame is extinguished and the excess fuel is discharged through the fuel exhaust port.

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