A micro-sized direct-injection premixed combustor

Abstract

The application belongs to the field of burner design, and particularly relates to a micro-size direct-injection premixed burner, which comprises a fuel inlet pipe, a fuel pressure stabilizing cavity, a micro-mixing pipe, a connecting arm and an end plate. The fuel inlet pipe, the fuel pressure stabilizing cavity and the micro-mixing pipe are sequentially arranged from front to back, and the fuel inlet pipe, the fuel pressure stabilizing cavity and the micro-mixing pipe are in communication with each other. Fuel is introduced into the fuel inlet pipe and flows into the fuel pressure stabilizing cavity. The micro-mixing pipe comprises a fuel pipe and an air pipe. One end of the fuel pipe is connected with the fuel pressure stabilizing cavity, and the other end of the fuel pipe is connected with one end of the air pipe. The other end of the air pipe is connected with a combustion chamber flame tube. The air pipe can receive air. The fuel in the fuel pressure stabilizing cavity is supplied into the air pipe in a direct-injection mode to mix with the air, and a premixed gas is supplied into the combustion chamber flame tube. The micro-size premixed combustion mode, the coaxial direct-injection fuel-air mixing scheme and the array micro-mixing pipe scheme can realize lower NOx emission when the synthetic gas is burned and improve the stability of the emission performance.

Description

Technical Field

[0001] This application belongs to the field of burner design, and specifically relates to a micro-sized direct injection premixed burner. Background Technology

[0002] Against the backdrop of "dual carbon" (carbon, oxygen, and carbon emissions), gas turbines urgently need to reduce carbon emissions during their application. One of the most effective measures currently is to replace the fossil fuels commonly used in gas turbines, such as natural gas, with low-carbon or zero-carbon fuels. In IGCC power plants, gas turbines can significantly reduce carbon emissions by burning syngas, contributing to the achievement of dual carbon goals. Compared to natural gas, syngas contains a higher volume fraction of H2, making it more prone to backfire during combustion in the combustion chamber, and resulting in higher NOx emissions.

[0003] The closest technology to this application is the micro-mixing diffusion burner, which achieves low NOx emissions through micro-sized diffusion flames.

[0004] It has the following disadvantages:

[0005] 1. High NOx emissions: Existing micro-sized diffusion flames have significant high-temperature flame regions, resulting in high NOx emissions when syngas is burned.

[0006] 2. Poor emission performance stability: Existing micro-sized diffusion combustion schemes use a transverse jet method for mixing fuel and air. Under different operating conditions, the fuel-air mixing performance deteriorates, which leads to poor emission performance and instability.

[0007] 3. High R&D costs: Due to the poor emission performance stability of existing micro-sized diffusion combustor solutions, a large amount of iterative and compromise design and testing work is required, resulting in high R&D costs.

[0008] Therefore, how to reduce NOx emissions and improve the stability of emission performance is a problem that needs to be solved. Summary of the Invention

[0009] To address the aforementioned issues, this application provides a micro-sized direct injection premixed burner to solve the problems of high NOx emissions and poor emission performance stability in existing direct injection premixed burners.

[0010] The technical solution of this application is: a micro-sized direct injection premixed burner, including a fuel inlet pipe, a fuel pressure stabilizing chamber, a micro-mixing pipe, a connecting arm, and an end plate;

[0011] The fuel inlet pipe, fuel pressure regulating chamber, and micro-mixing pipe are arranged sequentially from front to back, and are interconnected; fuel is introduced into the fuel inlet pipe and flows into the fuel pressure regulating chamber.

[0012] The micro-mixing pipe includes a fuel pipe and an air pipe. One end of the fuel pipe is connected to the fuel pressure stabilizing chamber, and the other end is connected to one end of the air pipe. The other end of the air pipe is connected to the combustion chamber flame tube.

[0013] The end plate is connected to the combustion chamber flame tube, and the connecting arm is connected between the fuel pressure stabilizing chamber and the end plate;

[0014] The air pipe can receive air, and the fuel in the fuel pressure stabilizing chamber is supplied into the air pipe by direct injection to mix with the air, forming a premixed gas that is then supplied to the combustion chamber flame tube.

[0015] Preferably, the end plate has a cylindrical cross-section, and the air pipes are multiple and arranged side by side on the end plate.

[0016] Preferably, four channels are provided inside the end plate, and no air pipes are arranged; the area near the center of the end plate is filled with air pipes, and no channels are provided.

[0017] Preferably, the end plate is provided with an ignition nozzle that is inserted into the combustion chamber flame tube, and the ignition nozzle is located in the surrounding position of the air pipe.

[0018] Preferably, the air flows into the air pipe through the gap between the fuel pressure regulating chamber, the end plate, and the diameter of the fuel pipe.

[0019] Preferably, there are multiple fuel pipes, each fuel pipe is connected to an air pipe, and the connected fuel pipes and air pipes are coaxially arranged.

[0020] The micro-sized direct injection premixed burner of this application has the following advantages:

[0021] By employing micro-sized premixed combustion, coaxial direct injection fuel-air mixing, and array micro-mixer design, lower NOx emissions, improved emission performance stability, and reduced R&D costs can be achieved when burning syngas. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of this application;

[0023] Figure 2 This is a structural diagram of the micro-mixing pipe and channel location in this application.

[0024] 1. Micro-mixing pipe; 2. Channel; 3. Ignition nozzle; 4. Fuel; 5. Fuel inlet pipe; 6. Fuel pressure regulating chamber; 7. Fuel pipe; 8. Connecting arm; 9. Air pipe; 10. Combustion chamber flame tube; 11. Air; 12. Premixed gas; 13. End plate. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0026] The first aspect of this application provides a micro-sized direct injection premixed burner, such as Figures 1-2 It includes a fuel inlet pipe 5, a fuel pressure regulating chamber 6, a micro-mixing pipe 1, a connecting arm 8, and an end plate 13.

[0027] The fuel inlet pipe 5, the fuel pressure regulating chamber 6, and the micro-mixing pipe 1 are arranged sequentially from front to back, and the fuel inlet pipe 5, the fuel pressure regulating chamber 6, and the micro-mixing pipe 1 are interconnected; fuel 4 is introduced into the fuel inlet pipe 5 and flows into the fuel pressure regulating chamber 6.

[0028] The micro-mixing pipe 1 includes a fuel pipe 7 and an air pipe 9. One end of the fuel pipe 7 is connected to the fuel pressure stabilizing chamber 6, and the other end is connected to one end of the air pipe 9. The other end of the air pipe 9 is connected to the combustion chamber flame tube 10.

[0029] End plate 13 is connected to combustion chamber flame tube 10, and connecting arm 8 is connected between fuel pressure stabilizing chamber 6 and end plate 13.

[0030] Air pipe 9 can receive air 11. Fuel 4 in fuel pressure stabilizing chamber 6 is supplied into air pipe 9 by direct injection and mixed with air 11 to form premixed gas 12, which is then supplied to combustion chamber flame tube 10.

[0031] The whole structure adopts a series connection structure of fuel inlet pipe 5-fuel pressure stabilizing chamber 6-micro-mixing pipe 1. Fuel 4 first enters the pressure stabilizing chamber for buffering and pressure stabilization, eliminating fuel 4 pressure fluctuations, ensuring uniform flow of fuel 4 into each micro-mixing pipe 1, and avoiding uneven fuel 4 supply in a single micro-mixing pipe 1, which can cause local high temperature and NOx increase.

[0032] The micro-mixer 1 adopts a coaxial premixing structure where fuel pipe 7 is directly injected into air pipe 9. Fuel 4 and air 11 are premixed inside air pipe 9 to form a uniform premixed gas 12. This abandons the existing diffusion combustion mode of mixing and burning simultaneously, significantly reducing the peak flame temperature and reducing the generation of thermal NOx from the source.

[0033] Preferably, the end plate 13 has a cylindrical cross-section, and multiple air pipes 9 are arranged side by side on the end plate 13. The parallel array of multiple air pipes 9 forms a large number of independent micro-scale premixed flames, which divides the overall combustion area into countless small flame units, increases the flame heat dissipation area, further suppresses local high-temperature zones, and continuously reduces NOx emissions.

[0034] Preferably, four channels 2 are provided within the end plate 13, without air pipes 9; the area near the center of the end plate 13 is filled with air pipes 9, without channels 2. The channels 2 without air pipes 9 at the edges 4 of the end plate 13 allow cooling air 11 to circulate, performing film cooling on the end plate 13 and the combustion chamber wall, reducing the heat load on components caused by high-temperature radiation, and extending the service life of the burner; at the same time, it balances the overall flow field of the end plate 13 and avoids the accumulation of airflow at the edges.

[0035] Preferably, an ignition nozzle 3 is provided inside the end plate 13 and inserted into the combustion chamber flame tube 10. The ignition nozzle 3 is located in the surrounding area of ​​the air pipe 9. The ignition nozzle 3 is arranged in the central area of ​​the densely packed micro-mixing pipes 1. At this location, the concentration of premixed gas 12 is moderate, the airflow velocity is stable, and the ignition energy is fully absorbed, which greatly improves the success rate of cold start ignition of the unit.

[0036] Preferably, air 11 flows into air pipe 9 through the gap between the fuel pressure stabilizing chamber 6, end plate 13 and the diameter of fuel pipe 7, and mixes with coaxial direct injection fuel 4 in the same direction, resulting in uniform disturbance of the mixed flow field.

[0037] Preferably, there are multiple fuel pipes 7, each fuel pipe 7 is connected to an air pipe 9, and the connected fuel pipes 7 and air pipes 9 are arranged coaxially.

[0038] In summary, this application has the following advantages:

[0039] 1. Reduce NOx emissions: This application adopts a micro-sized premixed combustion method to achieve a lower flame temperature when burning syngas, thereby reducing NOx emissions.

[0040] 2. Improve emission performance stability: This application adopts a micro-size direct injection fuel-air mixing method to achieve more stable fuel-air mixing uniformity, reduce the impact of operating conditions on mixing uniformity, and achieve more stable emission performance.

[0041] 3. Reduced R&D costs: This application uses coaxial direct injection micro-mixer tubes to burn syngas, resulting in more stable performance and reduced R&D costs. Furthermore, the use of an array of micro-mixer tubes to form the burner allows for the rapid development of burners composed of numerous micro-mixer tubes based on a single tube, further reducing R&D costs.

[0042] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A micro-sized direct injection premixed burner, characterized in that, It includes a fuel inlet pipe (5), a fuel pressure regulating chamber (6), a micro-mixing pipe (1), a connecting arm (8), and an end plate (13); The fuel inlet pipe (5), the fuel pressure regulating chamber (6), and the micro-mixing pipe (1) are arranged sequentially from front to back, and the fuel inlet pipe (5), the fuel pressure regulating chamber (6), and the micro-mixing pipe (1) are interconnected; fuel (4) is introduced into the fuel inlet pipe (5) and flows into the fuel pressure regulating chamber (6); The micro-mixing pipe (1) includes a fuel pipe (7) and an air pipe (9). One end of the fuel pipe (7) is connected to the fuel pressure stabilizing chamber (6), and the other end is connected to one end of the air pipe (9). The other end of the air pipe (9) is connected to the combustion chamber flame tube (10). The end plate (13) is connected to the combustion chamber flame tube (10), and the connecting arm (8) is connected between the fuel pressure stabilizing chamber (6) and the end plate (13); The air pipe (9) can receive air (11). The fuel (4) in the fuel pressure stabilizing chamber (6) is supplied into the air pipe (9) by direct injection and mixed with the air (11) to form a premixed gas (12) which is then supplied into the combustion chamber flame tube (10).

2. The micro-sized direct injection premixed burner as described in claim 1, characterized in that, The end plate (13) has a cylindrical cross section, and the air pipes (9) are multiple and arranged side by side on the end plate (13).

3. The micro-sized direct injection premixed burner as described in claim 2, characterized in that, Four channels (2) are provided in the end plate (13), but no air pipes (9) are arranged; the area near the center of the end plate (13) is filled with air pipes (9), but no channels (2) are provided.

4. The micro-sized direct injection premixed burner as described in claim 2, characterized in that, The end plate (13) is provided with an ignition nozzle (3) that is inserted into the combustion chamber flame tube (10), and the ignition nozzle (3) is located in the surrounding position of the air pipe (9).

5. The micro-sized direct injection premixed burner as described in claim 2, characterized in that, The air (11) flows into the air pipe (9) through the gap between the fuel pressure regulating chamber (6), the end plate (13) and the diameter of the fuel pipe (7).

6. The micro-sized direct injection premixed burner as described in claim 2, characterized in that, The fuel pipe (7) is also multiple, and each fuel pipe (7) is connected to an air pipe (9) in a corresponding manner. The connected fuel pipe (7) and air pipe (9) are coaxially arranged.

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