CN-118189218-B - Hydrogen-rich fuel premixing system for micro-mixing burner

Abstract

The application relates to the technical field of gas turbines, in particular to a hydrogen-rich fuel premixing system for a micro-mixed combustor, which comprises the following components: the Venturi mixing device is provided with three inlets and one outlet; the application firstly mixes hydrogen, air and natural gas into relatively uniform premixed fuel through a Venturi mixing device, the premixed fuel is respectively distributed into each mixing tube through a plurality of branches and is further mixed, and higher mixing degree is achieved near the outlet of the micro-mixed combustor, so that the mixing degree and uniformity of the premixed fuel are effectively improved.

Inventors

• ZHANG ZIJIAN
• LIU SHUAI
• Gao Chongzhe
• YIN HAIYU
• JIN DONGJIE
• ZHOU JIAJIA
• FENG DONGYANG
• LI DAN
• WANG WEI
• XIAO JUNFENG
• LIU XINHUI
• ZHANG XIUCHENG
• ZHANG PANDENG
• GAO SONG
• LI YUBIN
• LV WENJIE
• Ai Zeguang

Assignees

• 华能河南中原燃气发电有限公司
• 西安热工研究院有限公司

Dates

Publication Date

20260508

Application Date

20240419

Claims (10)

1. 1. A hydrogen-rich fuel premixing system for a micro-hybrid combustor, comprising: the venturi mixing device (7) is provided with three inlets (9) and an outlet (10), wherein the three inlets (9) are respectively connected with the natural gas supply structure (1), the hydrogen supply structure (2) and the air supply structure (3); the micro-mixed burner (8) is provided with a central nozzle (11) at the center, and a plurality of peripheral nozzle groups are arranged on the micro-mixed burner (8) around the central nozzle (11), wherein the central nozzle (11) is connected with a hydrogen-rich fuel supply structure (12) through a mixing pipe arranged in the micro-mixed burner (8); One end of each branch is connected with the outlet (10), and the other ends of the branches are respectively connected with the surrounding nozzle groups through mixing pipes arranged in the micro-mixed burner (8); one end of each branch is connected with the outlet (10) through a three-way joint; The other ends of the plurality of branches evenly distribute the premixed fuel to each peripheral nozzle (28) of the peripheral nozzle group in a tree form through a three-way joint; Or the other ends of the multiple branches distribute the premixed fuel evenly to each sub-branch in a tree form through a three-way joint, and the sub-branches distribute the premixed fuel evenly to each peripheral nozzle (28) of the peripheral nozzle group in a tree form through the three-way joint.
2. 2. Hydrogen-enriched fuel premixing system for micro-hybrid burners according to claim 1, characterized in that a pressure reducing valve (4) is provided on both the line connecting the inlet (9) with the natural gas supply structure (1) and the line connecting the inlet (9) with the hydrogen supply structure (2), and a valve (5) is provided on the line connecting the inlet (9) with the air supply structure (3).
3. 3. Hydrogen-rich fuel premixing system for micro-hybrid burners according to claim 2, characterized in that a mass flow meter (6) is provided on both the line connecting the pressure reducing valve (4) with the natural gas supply structure (1) and the line connecting the pressure reducing valve (4) with the hydrogen supply structure (2), and a mass flow meter (6) is provided on the line connecting the hydrogen-rich fuel supply structure (12) with the mixing tube.
4. 4. A hydrogen rich fuel premixing system for a micro-co-burner according to any one of claims 1-3, characterized in that each surrounding nozzle group consists of two surrounding nozzles (28).
5. 5. The hydrogen-enriched fuel premixing system for micro-mixed combustors according to claim 4, wherein the number of branches is two, namely a second branch (14) and a third branch (15), and the number of surrounding nozzle groups is two, namely a first surrounding nozzle group (18) and a second surrounding nozzle group (19); The second branch (14) is connected with two peripheral nozzles (28) of the first peripheral nozzle group (18) through two mixing pipes respectively, and the third branch (15) is connected with two peripheral nozzles (28) of the second peripheral nozzle group (19) through two mixing pipes respectively.
6. 6. The hydrogen-enriched fuel premixing system for micro-mixed combustors according to claim 5, characterized in that the second and third branches (14, 15) are connected to the outlet (10) by a first three-way joint adapted to equally distribute the mixed fuel outputted by the venturi mixing device (7) into the second and third branches (14, 15); the second branch (14) is connected with two peripheral nozzles (28) of the first peripheral nozzle group (18) through a second three-way joint, and the second three-way joint is suitable for evenly distributing 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 two peripheral nozzles (28) of the second peripheral nozzle group (19) by a third three-way joint adapted to equally distribute the mixed fuel of the third branch (15) into the two peripheral nozzles (28) of the second peripheral nozzle group (19).
7. 7. The hydrogen-enriched fuel premixing system for micro-mixed combustors according to claim 4, wherein the number of branches is two, namely a fourth branch (16) and a fifth branch (17), and the number of surrounding nozzle groups is four, namely a third surrounding nozzle group (20), a fourth surrounding nozzle group (21), a fifth surrounding nozzle group (22) and a sixth surrounding nozzle group (23); The fourth branch (16) is connected with the third peripheral nozzle group (20) and the fourth peripheral nozzle group (21) through a first sub-branch (24) and a second sub-branch (25), and the fifth branch (17) is connected with the fifth peripheral nozzle group (22) and the sixth peripheral nozzle group (23) through a third sub-branch (26) and a fourth sub-branch (27).
8. 8. The hydrogen-enriched fuel premixing system for a micro-mixed burner according to claim 7, characterized in that the first sub-branch (24) is connected to two peripheral nozzles (28) of the third peripheral nozzle group (20) by two mixing pipes, the second sub-branch (25) is connected to two peripheral nozzles (28) of the fourth peripheral nozzle group (21) by two mixing pipes, the third sub-branch (26) is connected to two peripheral nozzles (28) of the fifth peripheral nozzle group (22) by two mixing pipes, and the fourth sub-branch (27) is connected to two peripheral nozzles (28) of the sixth peripheral nozzle group (23) by two mixing pipes.
9. 9. The hydrogen-enriched fuel premixing system for micro-mixed combustors according to claim 8, characterized in that the fourth branch (16), the fifth branch (17) are connected with the outlet (10) through a fourth three-way joint adapted to equally distribute the mixed fuel outputted by the venturi mixing device (7) into the fourth branch (16) and the fifth branch (17); The first sub-branch (24) and the second sub-branch (25) are connected with the fourth branch (16) through a fifth three-way joint, and the fifth three-way joint is suitable for evenly distributing 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 with the fifth branch (17) through a sixth three-way joint, and the sixth three-way joint is suitable for evenly distributing the mixed fuel of the fifth branch (17) into the third sub-branch (26) and the fourth sub-branch (27); The first sub-branch (24) is connected to two peripheral nozzles (28) of the third peripheral nozzle group (20) by a seventh three-way joint adapted to equally distribute the mixed fuel of the first sub-branch (24) to the two peripheral nozzles (28) of the third peripheral nozzle group (20); The second sub-branch (25) is connected with two peripheral nozzles (28) of the fourth peripheral nozzle group (21) through an eighth three-way joint, and the eighth three-way joint is suitable for evenly distributing the mixed fuel of 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) by a ninth three-way joint adapted to equally distribute the mixed fuel of the third sub-branch (26) to 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) by a tenth three-way joint, the thirteenth joint being adapted to equally distribute the mixed fuel of the fourth sub-branch (27) into two peripheral nozzles (28) of the sixth peripheral nozzle group (23).
10. 10. Hydrogen-rich fuel premixing system for micro-hybrid burners according to claim 8 or 9, characterized in that mass flow means (6) are provided on both the first sub-branch (24) and the third sub-branch (26).

Description

Hydrogen-rich fuel premixing system for micro-mixing burner Technical Field The invention relates to the technical field of gas turbines, in particular to a hydrogen-rich fuel premixing system for a micro-mixed combustor. Background In-service heavy gas turbines generally adopt a traditional strong swirl lean premixed combustion technology, and natural gas is used as a main fuel. With the increasing strictness of environmental protection requirements, hydrogen energy is widely utilized, and generally, hydrogen is doped into fuel of a gas turbine or pure hydrogen is directly adopted as fuel of the gas turbine. The fuel that incorporates hydrogen is also referred to as a hydrogen-rich fuel, and the pure hydrogen fuel is also referred to as a pure hydrogen fuel. However, the combustion and emission characteristics of hydrogen and natural gas are quite different, and the flame propagation speed of hydrogen is very fast, which results in a great risk of flame flashback when the gas turbine is premixed. The existing strong swirl lean premixed combustion technology is not suitable for the combustion of hydrogen-rich fuel and pure hydrogen fuel. The micro-mixed burner abandons the traditional swirl large nozzle, adopts a plurality of micro-tubes with the inner diameter of 2 mm-10 mm, has NO backflow area in the flow field of the micro-mixed burner, has very high tempering resistance and can reduce the discharge of NO x to a certain extent. However, since the micro-hybrid combustor includes a plurality of micro-nozzles, the thorough mixing and uniform distribution of the air flow near the outlet of each micro-nozzle will directly affect the combustion stability, combustion efficiency, and pollutant emissions characteristics of the gas turbine. For the existing micro-mixed combustors, especially for the relatively less cases that the number of micro-tubes is not more than 10, a three-way joint or a four-way joint is often adopted to directly mix and distribute fuel and air, or directly complete mixing in a nozzle. The method for mixing and distributing the air flow is simple and easy to operate, but for turbulent jet flow with high flow speed, the stay time of the turbulent jet flow is short, and the turbulent jet flow only depends on the micro-tubule to carry out along-distance mixing, so that the mixing degree is low, and the effect is not ideal. In the case where the number of branch pipes is 4 or more, the length, angle, position, and the like of each branch pipe are difficult to be strictly uniform, and therefore there is often a problem of uneven flow distribution. Disclosure of Invention Therefore, the technical problem to be solved by the invention is to overcome the defects of low and uneven fuel mixing degree caused by short residence time of turbulent jet flow in a micro-fine tube in the micro-mixed combustor. To overcome the above-described drawbacks, the present invention provides a hydrogen-enriched fuel premixing system for a micro-hybrid combustor, comprising: the venturi mixing device is provided with three inlets and an outlet, wherein the three inlets are respectively connected with the natural gas supply structure, the hydrogen supply structure and the air supply structure; The micro-mixed burner is provided with a central nozzle at the center, and a plurality of peripheral nozzle groups are arranged on the micro-mixed burner around the central nozzle; and one end of each branch is connected with the outlet, and the other ends of the branches are respectively connected with the surrounding nozzle groups through mixing pipes arranged in the micro-mixed burner. Optionally, pressure reducing valves are arranged on the pipeline of the inlet connected with the natural gas supply structure and the pipeline of the inlet connected with the hydrogen supply structure, and valves are arranged on the pipeline of the inlet connected with the air supply structure. Optionally, a mass flow device is arranged on a pipeline connected with the pressure reducing valve and the natural gas supply structure and a pipeline connected with the pressure reducing valve and the hydrogen supply structure, and a mass flow device is arranged on a pipeline connected with the hydrogen-rich fuel supply structure and the mixing pipe. Alternatively, each peripheral nozzle group is composed of two peripheral nozzles, the two peripheral nozzles of each peripheral nozzle group being disposed in close proximity. Optionally, the number of the branches is two, namely a second branch and a third branch; the number of the peripheral nozzle groups is two, namely a first peripheral nozzle group and a second peripheral nozzle group; The second branch is connected with two peripheral nozzles of the first peripheral nozzle group through two mixing pipes respectively, and the third branch is connected with two peripheral nozzles of the second peripheral nozzle group through two mixing pipes respectively. The first three-way joint is suitable for e