A hydrogen-rich fuel premixing system for a micro- combustor

Abstract

The application relates to the technical field of gas turbines, in particular to a hydrogen-rich fuel premixing system for a micro-mixing combustor, which comprises a Venturi mixing device provided with three inlets and one outlet; the three inlets are connected with a natural gas supply structure, a hydrogen gas supply structure and an air supply structure respectively; a plurality of surrounding nozzle groups are arranged around the center on the micro-mixing combustor; one end of a plurality of branches is connected with the outlet, and the other end is connected with the surrounding nozzle groups through mixing pipes arranged in the micro-mixing combustor; the hydrogen gas, the air and the natural gas are mixed by the Venturi mixing device to form relatively uniform premixed fuel; the premixed fuel is distributed into the mixing pipes through the plurality of branches respectively, is further mixed, and reaches a higher mixing degree near the outlet of the micro-mixing combustor; and the degree and uniformity of premixed fuel mixing are effectively improved.

Description

Technical Field

[0001] This invention relates to the field of gas turbine technology, and more specifically to a hydrogen-rich fuel premixing system for a micro-hybrid combustor. Background Technology

[0002] Heavy-duty gas turbines in service generally employ traditional strong swirl lean premixed combustion technology, using natural gas as the primary fuel. With increasingly stringent environmental regulations, hydrogen energy is being widely utilized; this typically involves blending hydrogen into the gas turbine fuel or using pure hydrogen directly. Fuels blended with hydrogen are known as hydrogen-rich fuels; pure hydrogen fuels are known as pure hydrogen fuels. However, hydrogen and natural gas have significantly different combustion and emission characteristics; hydrogen's flame propagation speed is extremely fast, leading to a high risk of flame backfire during premixed combustion in gas turbines. The currently used strong swirl lean premixed combustion technology is not suitable for the combustion of hydrogen-rich or pure hydrogen fuels.

[0003] The micro-mixer burner abandons the traditional large swirl nozzle; instead, it uses multiple micro-tubes with inner diameters ranging from 2mm to 10mm. This eliminates the backflow zone in the micro-mixer's flow field, resulting in high resistance to flashback and reducing NO₂ levels to some extent. x However, since the micro-hybrid combustor contains multiple micro-nozzles, the thorough mixing and uniform distribution of the airflow near the outlet of each micro-nozzle will directly affect the combustion stability, combustion efficiency, and pollutant emission characteristics of the gas turbine.

[0004] For existing micro-mixer burners, especially those with a relatively small number of micro-tubes (no more than 10), tee or four-way connectors are often used to directly mix and distribute fuel and air, or mixing is completed directly within the nozzle. While these methods of airflow mixing and distribution are simple and easy to operate, for high-velocity turbulent jets, the residence time is very short, and mixing along the flow path within the micro-tubes results in a low degree of mixing and is not ideal. Furthermore, for cases with four or more branch lines, the length, angle, and position of each branch line are difficult to strictly uniform, often leading to uneven flow distribution. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the turbulent jet in the micro-tube has a very short residence time, resulting in low and uneven fuel mixing.

[0006] To overcome the above-mentioned shortcomings, the present invention provides a hydrogen-rich fuel premixing system for a micro-hybrid combustor, comprising:

[0007] The Venturi mixing unit has three inlets and one outlet; the three inlets are respectively connected to a natural gas supply structure, a hydrogen supply structure, and an air supply structure.

[0008] The micro-hybrid burner has a central nozzle and a plurality of peripheral nozzle groups arranged around the central nozzle; the central nozzle is connected to a hydrogen-rich fuel supply structure through a mixing pipe provided inside the micro-hybrid burner.

[0009] Multiple branches, one end of which is connected to the outlet, and the other end of each branch is connected to the surrounding nozzle assembly through a mixing pipe provided inside the micro-mixer burner.

[0010] Optionally, pressure reducing valves are provided on the pipeline connecting the inlet to the natural gas supply structure and on the pipeline connecting the inlet to the hydrogen supply structure; a valve is provided on the pipeline connecting the inlet to the air supply structure.

[0011] Optionally, a mass flow meter is provided on the pipeline connecting the pressure reducing valve to the natural gas supply structure and on the pipeline connecting the pressure reducing valve to the hydrogen supply structure; a mass flow meter is also provided on the pipeline connecting the hydrogen-rich fuel supply structure to the mixing pipe.

[0012] Optionally, each surrounding nozzle group consists of two surrounding nozzles; the two surrounding nozzles of each surrounding nozzle group are positioned close to each other.

[0013] Optionally, the number of branches is two, namely: a second branch and a third branch; the number of surrounding nozzle groups is two, namely: a first surrounding nozzle group and a second surrounding nozzle group;

[0014] The second branch is connected to the two peripheral nozzles of the first peripheral nozzle group via two mixing pipes; the third branch is connected to the two peripheral nozzles of the second peripheral nozzle group via two mixing pipes.

[0015] Optionally, the second branch and the third branch are connected to the outlet via a first tee connector; the first tee connector is adapted to evenly distribute the mixed fuel output from the Venturi mixer into the second branch and the third branch;

[0016] The second branch is connected to the two peripheral nozzles of the first peripheral nozzle group via a second tee connector; the second tee connector is adapted to evenly distribute the mixed fuel of the second branch into the two peripheral nozzles of the first peripheral nozzle group.

[0017] The third branch is connected to the two peripheral nozzles of the second peripheral nozzle group via a third tee connector; the third tee connector is adapted to evenly distribute the mixed fuel of the third branch into the two peripheral nozzles of the second peripheral nozzle group.

[0018] Optionally, the number of branches is two, namely: the fourth branch and the fifth branch; the number of surrounding nozzle groups is four, namely: the third surrounding nozzle group, the fourth surrounding nozzle group, the fifth surrounding nozzle group and the sixth surrounding nozzle group;

[0019] The fourth branch is connected to the third and fourth surrounding nozzle groups via the first and second sub-branches, respectively; the fifth branch is connected to the fifth and sixth surrounding nozzle groups via the third and fourth sub-branches, respectively.

[0020] Optionally, the first sub-branch is connected to two peripheral nozzles of the third peripheral nozzle group via two mixing pipes; the second sub-branch is connected to two peripheral nozzles of the fourth peripheral nozzle group via two mixing pipes; the third sub-branch is connected to two peripheral nozzles of the fifth peripheral nozzle group via two mixing pipes; and the fourth sub-branch is connected to two peripheral nozzles of the sixth peripheral nozzle group via two mixing pipes.

[0021] Optionally, the fourth and fifth branches are connected to the outlet via a fourth tee connector; the fourth tee connector is adapted to evenly distribute the mixed fuel output from the Venturi mixer into the fourth and fifth branches;

[0022] The first sub-branch and the second sub-branch are connected to the fourth branch via a fifth tee connector; the fifth tee connector is adapted to evenly distribute the mixed fuel of the fourth branch into the first sub-branch and the second sub-branch.

[0023] The third sub-branch and the fourth sub-branch are connected to the fifth branch via a sixth tee connector; the sixth tee connector is adapted to evenly distribute the mixed fuel of the fifth branch into the third sub-branch and the fourth sub-branch.

[0024] The first sub-branch is connected to two peripheral nozzles of the third peripheral nozzle group via a seventh tee connector; the seventh tee connector is adapted to evenly distribute the mixed fuel of the first sub-branch into the two peripheral nozzles of the third peripheral nozzle group.

[0025] The second sub-branch is connected to the two peripheral nozzles of the fourth peripheral nozzle group via an eighth tee connector; the eighth tee connector is adapted to evenly distribute the mixed fuel of the second sub-branch into the two peripheral nozzles of the fourth peripheral nozzle group.

[0026] The third sub-branch is connected to the two peripheral nozzles of the fifth peripheral nozzle group via a ninth three-way connector; the ninth three-way connector is adapted to evenly distribute the mixed fuel of the third sub-branch into the two peripheral nozzles of the fifth peripheral nozzle group.

[0027] The fourth sub-branch is connected to the two peripheral nozzles of the sixth peripheral nozzle group via a thirteenth connector; the thirteenth connector is adapted to evenly distribute the mixed fuel of the fourth sub-branch into the two peripheral nozzles of the sixth peripheral nozzle group.

[0028] Optionally, a mass flow meter is provided on both the first sub-branch and the third sub-branch.

[0029] The technical solution of the present invention has the following advantages compared with the prior art:

[0030] 1. The present invention provides a hydrogen-rich fuel premixing system for a micro-mixing burner, comprising: a Venturi mixing device with three inlets and one outlet; the three inlets being connected to a natural gas supply structure, a hydrogen supply structure, and an air supply structure, respectively; a micro-mixing burner with a central nozzle and a plurality of peripheral nozzle groups surrounding the central nozzle; the central nozzle being connected to the hydrogen-rich fuel supply structure via a mixing pipe within the micro-mixing burner; and multiple branches, one end of which is connected to the outlet, and the other end of each branch being connected to the peripheral nozzle groups via mixing pipes within the micro-mixing burner. This application employs the above technical solution, firstly mixing hydrogen, air, and natural gas through the Venturi mixing device to form a relatively uniform premixed fuel; the premixed fuel is then distributed to each mixing pipe via multiple branches for further mixing, achieving a higher degree of mixing near the outlet of the micro-mixing burner; effectively improving the degree and uniformity of premixed fuel mixing.

[0031] 2. In this invention, a mass flow meter is provided on the pipeline connecting the pressure reducing valve to the natural gas supply structure and on the pipeline connecting the pressure reducing valve to the hydrogen supply structure; a mass flow meter is also provided on the pipeline connecting the hydrogen-rich fuel supply structure to the mixing pipe; this application adopts the above technical solution, and the mass flow meter facilitates the adjustment and control of the gas flow rate passing through the mass flow meter.

[0032] 3. In this invention, the second and third branches are connected to the outlet via a first tee connector; the first tee connector is adapted to evenly distribute the mixed fuel output from the Venturi mixer into the second and third branches; the second branch is connected to two peripheral nozzles of the first peripheral nozzle group via a second tee connector; the second tee connector is adapted to evenly distribute the mixed fuel of the second branch into the two peripheral nozzles of the first peripheral nozzle group; the third branch is connected to two peripheral nozzles of the second peripheral nozzle group via a third tee connector; the third tee connector is adapted to evenly distribute the mixed fuel of the third branch into the two peripheral nozzles of the second peripheral nozzle group; this application adopts the above technical solution to evenly distribute the premixed fuel to each part in a tree-like manner, and then evenly divides the airflow of each part into two paths to supply into the mixing pipe; further effectively improving the uniformity of the premixed fuel in each mixing pipe.

[0033] 4. In this invention, mass flow meters are provided on both the first sub-branch and the third sub-branch. In this application, the above technical solution is adopted. Since the number of surrounding nozzle groups is relatively large, mass flow meters are added to monitor, adjust and control the flow rate. Attached Figure Description

[0034] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0035] Figure 1 This is a connection diagram of the hydrogen-rich fuel premixing system for a micro-hybrid burner provided in Embodiment 1 of the present invention.

[0036] Figure 2 This is a schematic diagram of the micro-hybrid burner provided in Embodiment 1 of the present invention located on one side of the central nozzle;

[0037] Figure 3 This is a connection diagram of the hydrogen-rich fuel premixing system for a micro-hybrid burner provided in Embodiment 2 of the present invention;

[0038] Figure 4 This is a schematic diagram of the micro-mixer burner provided in Embodiment 2 of the present invention located on one side of the central nozzle.

[0039] Explanation of reference numerals in the attached figures:

[0040] 1. Natural gas supply structure; 2. Hydrogen supply structure; 3. Air supply structure; 4. Pressure reducing valve; 5. Valve; 6. Mass flow meter; 7. Venturi mixer; 8. Micro-mixer burner; 9. Inlet; 10. Outlet; 11. Center nozzle; 12. Hydrogen-rich fuel supply structure; 13. First branch; 14. Second branch; 15. Third branch; 16. Fourth branch; 17. Fifth branch; 18. First surrounding nozzle group; 19. Second surrounding nozzle group; 20. Third surrounding nozzle group; 21. Fourth surrounding nozzle group; 22. Fifth surrounding nozzle group; 23. Sixth surrounding nozzle group; 24. First sub-branch; 25. Second sub-branch; 26. Third sub-branch; 27. Fourth sub-branch; 28. Surrounding nozzle. Detailed Implementation

[0041] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0044] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0045] Implementation Method 1

[0046] like Figures 1 to 2 One embodiment of the hydrogen-rich fuel premixing system for a micro-hybrid burner, as shown, includes: a Venturi mixer 7, a micro-hybrid burner 8, and multiple branches. The premixed fuel output from the hydrogen-rich fuel premixing system for the micro-hybrid burner can be combusted in the combustion chamber.

[0047] like Figure 2 As shown, the micro-mixer burner 8 has a central nozzle 11 at its center, and a plurality of peripheral nozzle groups are arranged around the central nozzle 11 on the micro-mixer burner 8. Each peripheral nozzle group consists of two peripheral nozzles 28; the two peripheral nozzles 28 in each peripheral nozzle group can be arranged close to each other.

[0048] like Figure 1As shown, the Venturi mixing device 7 has three inlets 9 and one outlet 10; the outlet 10 can be located at the top. The three inlets 9 are respectively connected to the natural gas supply structure 1, the hydrogen supply structure 2, and the air supply structure 3. The central nozzle 11 is connected to the hydrogen-rich fuel supply structure 12 via a mixing pipe provided in the micro-mixer burner 8 through a first branch 13. The inner diameter of the mixing pipe is 2mm to 10mm. One end of the multiple branches is connected to the outlet 10, and the other end of the multiple branches is connected to the surrounding nozzle group via a mixing pipe provided in the micro-mixer burner 8. Specifically, there are two branches: a second branch 14 and a third branch 15; there are two surrounding nozzle groups: a first surrounding nozzle group 18 and a second surrounding nozzle group 19. The second branch 14 is connected to two surrounding nozzles 28 of the first surrounding nozzle group 18 via two mixing pipes; the third branch 15 is connected to two surrounding nozzles 28 of the second surrounding nozzle group 19 via two mixing pipes. More specifically, the second branch 14 and the third branch 15 are connected to the outlet 10 via a first tee connector; the first tee connector is adapted to evenly distribute the mixed fuel output from the Venturi mixer 7 into the second branch 14 and the third branch 15. The second branch 14 is connected to the two peripheral nozzles 28 of the first peripheral nozzle group 18 via a second tee connector; the second tee connector is adapted to evenly distribute the mixed fuel of the second branch 14 into the two peripheral nozzles 28 of the first peripheral nozzle group 18. The third branch 15 is connected to the two peripheral nozzles 28 of the second peripheral nozzle group 19 via a third tee connector; the third tee connector is adapted to evenly distribute the mixed fuel of the third branch 15 into the two peripheral nozzles 28 of the second peripheral nozzle group 19. Wherein, in Figure 1 The arrows indicate the direction of gas flow. The gas can be natural gas, hydrogen, air, premixed fuel, or hydrogen-rich fuel.

[0049] like Figure 1 As shown, pressure reducing valves 4 are installed on the pipelines connecting inlet 9 to the natural gas supply structure 1 and to the hydrogen supply structure 2; a valve 5 is installed on the pipeline connecting inlet 9 to the air supply structure 3. Specifically, the valve 5 can be a ball valve. Mass flow meters 6 are installed on the pipelines connecting pressure reducing valve 4 to the natural gas supply structure 1 and to the hydrogen supply structure 2; a mass flow meter 6 is also installed on the pipeline connecting the hydrogen-rich fuel supply structure 12 to the mixing pipe.

[0050] The hydrogen-rich fuel premixing system for micro-hybrid burners described in this application employs a method of separately supplying hydrogen-rich fuel gas to the central nozzle 11, and combining a Venturi mixing device 7 with flow zone control to supply premixed fuel to the surrounding nozzle group. During actual installation, interlocking and collision between connecting pipelines should be avoided.

[0051] Implementation Method 2

[0052] like Figures 3 to 4 Another specific embodiment of the hydrogen-rich fuel premixing system for a micro-hybrid burner is shown.

[0053] like Figure 4 As shown, there are four groups of surrounding nozzles: the third surrounding nozzle group 20, the fourth surrounding nozzle group 21, the fifth surrounding nozzle group 22, and the sixth surrounding nozzle group 23.

[0054] like Figure 3 As shown, the micro-hybrid burner 8 is surrounded by an ellipse, and the specific connection relationship is described below. There are two branches: a fourth branch 16 and a fifth branch 17. The fourth branch 16 is connected to the third surrounding nozzle group 20 and the fourth surrounding nozzle group 21 via a first sub-branch 24 and a second sub-branch 25, respectively. The fifth branch 17 is connected to the fifth surrounding nozzle group 22 and the sixth surrounding nozzle group 23 via a third sub-branch 26 and a fourth sub-branch 27, respectively. Specifically, the first sub-branch 24 is connected to the two surrounding nozzles 28 of the third surrounding nozzle group 20 via two mixing pipes; the second sub-branch 25 is connected to the two surrounding nozzles 28 of the fourth surrounding nozzle group 21 via two mixing pipes; the third sub-branch 26 is connected to the two surrounding nozzles 28 of the fifth surrounding nozzle group 22 via two mixing pipes; and the fourth sub-branch 27 is connected to the two surrounding nozzles 28 of the sixth surrounding nozzle group 23 via two mixing pipes.

[0055] More specifically, the fourth branch 16 and the fifth branch 17 are connected to the outlet 10 via a fourth tee connector; the fourth tee connector is adapted to evenly distribute the mixed fuel output from the Venturi mixer 7 into the fourth branch 16 and the fifth branch 17. The first sub-branch 24 and the second sub-branch 25 are connected to the fourth branch 16 via a fifth tee connector; the fifth tee connector is adapted to evenly distribute the mixed fuel from the fourth branch 16 into the first sub-branch 24 and the second sub-branch 25. The third sub-branch 26 and the fourth sub-branch 27 are connected to the fifth branch 17 via a sixth tee connector; the sixth tee connector is adapted to evenly distribute the mixed fuel from the fifth branch 17 into the third sub-branch 26 and the fourth sub-branch 27. The first sub-branch 24 is connected to the two peripheral nozzles 28 of the third peripheral nozzle group 20 via a seventh tee connector; the seventh tee connector is adapted to evenly distribute the mixed fuel from the first sub-branch 24 into the two peripheral nozzles 28 of the third peripheral nozzle group 20. The second sub-branch 25 is connected to two peripheral nozzles 28 of the fourth peripheral nozzle group 21 via an eighth tee connector; the eighth tee connector is adapted to evenly distribute the mixed fuel from the second sub-branch 25 into the two peripheral nozzles 28 of the fourth peripheral nozzle group 21. The third sub-branch 26 is connected to two peripheral nozzles 28 of the fifth peripheral nozzle group 22 via a ninth tee connector; the ninth tee connector is adapted to evenly distribute the mixed fuel from the third sub-branch 26 into the two peripheral nozzles 28 of the fifth peripheral nozzle group 22. The fourth sub-branch 27 is connected to two peripheral nozzles of the sixth peripheral nozzle group 23 via a thirteenth tee connector; the thirteenth tee connector is adapted to evenly distribute the mixed fuel from the fourth sub-branch 27 into the two peripheral nozzles 28 of the sixth peripheral nozzle group 23.

[0056] Furthermore, mass flow meters 6 are provided on both the first sub-branch 24 and the third sub-branch 26.

[0057] Among them, Figure 3 The arrows indicate the direction of gas flow. The gas can be natural gas, hydrogen, air, premixed fuel, or hydrogen-rich fuel.

[0058] Other technical solutions are the same as in Implementation Method 1.

[0059] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A hydrogen-rich fuel premixing system for a micro-hybrid burner, characterized in that, include: The Venturi mixing unit (7) has three inlets (9) and one outlet (10); the three inlets (9) are respectively connected to the natural gas supply structure (1), the hydrogen supply structure (2), and the air supply structure (3); The micro-hybrid burner (8) has a central nozzle (11) and a plurality of peripheral nozzle groups are provided around the central nozzle (11) on the micro-hybrid burner (8); the central nozzle (11) is connected to the hydrogen-rich fuel supply structure (12) through a mixing pipe provided inside the micro-hybrid burner (8). Multiple branches, one end of which is connected to the outlet (10), and the other end of the multiple branches is connected to the surrounding nozzle group through the mixing pipe provided in the micro-mixer (8); One end of each of the multiple branches is connected to the outlet (10) via a T-joint; The other end of the multiple branches distributes the premixed fuel evenly to the various peripheral nozzles of the peripheral nozzle group in a tree-like manner via a T-joint. Alternatively, the other end of the multiple branches may be connected to a T-junction to distribute the premixed fuel evenly to each sub-branch in a tree-like manner; the sub-branch may be connected to a T-junction to distribute the premixed fuel evenly to each of the surrounding nozzles (28) of the surrounding nozzle group in a tree-like manner.

2. The hydrogen-rich fuel premixing system for a micro-hybrid burner according to claim 1, characterized in that, Pressure reducing valves (4) are provided on the pipeline connecting the inlet (9) to the natural gas supply structure (1) and on the pipeline connecting the inlet (9) to the hydrogen supply structure (2); valves (5) are provided on the pipeline connecting the inlet (9) to the air supply structure (3).

3. The hydrogen-rich fuel premixing system for a micro-hybrid combustor according to claim 2, characterized in that, Mass flow meters (6) are provided on the pipeline connecting the pressure reducing valve (4) to the natural gas supply structure (1) and on the pipeline connecting the pressure reducing valve (4) to the hydrogen supply structure (2); mass flow meters (6) are provided on the pipeline connecting the hydrogen-rich fuel supply structure (12) to the mixing pipe.

4. The hydrogen-rich fuel premixing system for a micro-hybrid combustor according to any one of claims 1-3, characterized in that, Each surrounding nozzle group consists of two surrounding nozzles (28).

5. The hydrogen-rich fuel premixing system for a micro-hybrid combustor according to claim 4, characterized in that, The number of branches is two, namely: the second branch (14) and the third branch (15); the number of surrounding nozzle groups is two, namely the first surrounding nozzle group (18) and the second surrounding nozzle group (19). The second branch (14) is connected to the two peripheral nozzles (28) of the first peripheral nozzle group (18) via two mixing pipes; the third branch (15) is connected to the two peripheral nozzles (28) of the second peripheral nozzle group (19) via two mixing pipes.

6. The hydrogen-rich fuel premixing system for a micro-hybrid combustor according to claim 5, characterized in that, The second branch (14) and the third branch (15) are connected to the outlet (10) through the first tee connector; the first tee connector is adapted to evenly distribute the mixed fuel output by the Venturi mixer (7) into the second branch (14) and the third branch (15). The second branch (14) is connected to the two peripheral nozzles (28) of the first peripheral nozzle group (18) via a second tee connector; the second tee connector is adapted to distribute the mixed fuel of the second branch (14) evenly into the two peripheral nozzles (28) of the first peripheral nozzle group (18). The third branch (15) is connected to the two peripheral nozzles (28) of the second peripheral nozzle group (19) via a third tee connector; the third tee connector is adapted to distribute the mixed fuel of the third branch (15) evenly into the two peripheral nozzles (28) of the second peripheral nozzle group (19).

7. The hydrogen-rich fuel premixing system for a micro-hybrid combustor according to claim 4, characterized in that, The number of branches is two, namely: the fourth branch (16) and the fifth branch (17); the number of surrounding nozzle groups is four, namely the third surrounding nozzle group (20), the fourth surrounding nozzle group (21), the fifth surrounding nozzle group (22) and the sixth surrounding nozzle group (23). The fourth branch (16) is connected to the third surrounding nozzle group (20) and the fourth surrounding nozzle group (21) through the first sub-branch (24) and the second sub-branch (25), respectively; the fifth branch (17) is connected to the fifth surrounding nozzle group (22) and the sixth surrounding nozzle group (23) through the third sub-branch (26) and the fourth sub-branch (27), respectively.

8. The hydrogen-rich fuel premixing system for a micro-hybrid combustor according to claim 7, characterized in that, The first sub-branch (24) is connected to the two surrounding nozzles (28) of the third surrounding nozzle group (20) through two mixing pipes respectively; the second sub-branch (25) is connected to the two surrounding nozzles (28) of the fourth surrounding nozzle group (21) through two mixing pipes respectively; the third sub-branch (26) is connected to the two surrounding nozzles (28) of the fifth surrounding nozzle group (22) through two mixing pipes respectively; the fourth sub-branch (27) is connected to the two surrounding nozzles (28) of the sixth surrounding nozzle group (23) through two mixing pipes respectively.

9. The hydrogen-rich fuel premixing system for a micro-hybrid combustor according to claim 8, characterized in that, The fourth branch (16) and the fifth branch (17) are connected to the outlet (10) via the fourth tee connector; the fourth tee connector is adapted to evenly distribute the mixed fuel output from the Venturi mixer (7) into the fourth branch (16) and the fifth branch (17). The first sub-branch (24) and the second sub-branch (25) are connected to the fourth branch (16) via a fifth tee connector; the fifth tee connector is adapted to evenly distribute the mixed fuel of the fourth branch (16) into the first sub-branch (24) and the second sub-branch (25). The third sub-branch (26) and the fourth sub-branch (27) are connected to the fifth sub-branch (17) via a sixth tee connector; the sixth tee connector is adapted to evenly distribute the mixed fuel of the fifth sub-branch (17) into the third sub-branch (26) and the fourth sub-branch (27). The first sub-branch (24) is connected to the two peripheral nozzles (28) of the third peripheral nozzle group (20) via a seventh tee connector; the seventh tee connector is adapted to evenly distribute the mixed fuel of the first sub-branch (24) into the two peripheral nozzles (28) of the third peripheral nozzle group (20). The second sub-branch (25) is connected to the two peripheral nozzles (28) of the fourth peripheral nozzle group (21) via an eighth tee connector; the eighth tee connector is adapted to distribute the mixed fuel of the second sub-branch (25) evenly into the two peripheral nozzles (28) of the fourth peripheral nozzle group (21). The third sub-branch (26) is connected to the two peripheral nozzles (28) of the fifth peripheral nozzle group (22) via a ninth three-way connector; the ninth three-way connector is adapted to distribute the mixed fuel of the third sub-branch (26) evenly into the two peripheral nozzles (28) of the fifth peripheral nozzle group (22). The fourth sub-branch (27) is connected to the two peripheral nozzles of the sixth peripheral nozzle group (23) via a thirteenth connector; the thirteenth connector is adapted to distribute the mixed fuel of the fourth sub-branch (27) evenly into the two peripheral nozzles (28) of the sixth peripheral nozzle group (23).

10. The hydrogen-rich fuel premixing system for a micro-hybrid combustor according to claim 8 or 9, characterized in that, Mass flow meters (6) are provided on both the first sub-branch (24) and the third sub-branch (26).

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