A hydrogen injection system and flame stabilization method for a gas turbine

Abstract

A hydrogen injection system for a gas turbine includes a hydrogen storage tank connected to a hydrogen injector for directly injecting hydrogen into a combustion chamber at a set flow rate. The present invention has two hydrogen injectors, namely a first hydrogen injector with a nozzle located at the lower position of the combustion chamber side wall and a second hydrogen injector with a nozzle located at the bottom of the combustion chamber. The present invention also provides a flame stabilization method using this system, in which air and fuel are metered separately and mixed and sent into the combustion chamber, and then hydrogen is metered and directly injected into the combustion chamber from the bottom or side at a set flow rate for ignition and combustion. The present invention uses natural gas and hydrogen as fuel, and the directly injected hydrogen accounts for 1%-5% of the total fuel. The present invention can further expand the lean burn limit of combustion by injecting a small amount of hydrogen while stabilizing the flame, improve the fuel ignition performance and combustion efficiency, reduce the risks of flashback, self-ignition, and thermoacoustic oscillation during combustion, and limit the emission of pollutants such as nitrogen oxides.

Description

Technical Field

[0001] The present invention belongs to the field of energy and power technology, and in particular relates to a hydrogen injection system and a flame stabilization method for a gas turbine. Background Art

[0002] Gas turbines are state-of-the-art heat-to-power conversion devices. Typical heavy-duty gas turbines for power generation use natural gas as fuel and employ lean premixed combustion, resulting in low NOx emissions. Hydrogen is an excellent energy carrier, and green hydrogen (hydrogen produced from renewable energy) can effectively absorb fluctuating wind, solar, and hydropower. Converting fluctuating renewable energy into hydrogen, and then converting it into stable outputs such as electricity, cooling, and heat through combustion and fuel cells, is a viable low-carbon, distributed energy utilization solution. Compared to traditional hydrocarbon fuels, hydrogen offers advantages such as lower ignition energy, faster flame propagation, a wider flammability range, higher thermal efficiency, low NOx emissions, zero HC, CO, or the greenhouse gas CO2, and is renewable. Blending hydrogen with natural gas as a fuel leverages the strengths of both fuels, offsetting their shortcomings and meeting increasingly stringent emission and economic requirements. Relevant research shows that hydrogen blending can expand the lean burn limit of combustion and effectively widen the operating envelope of the gas turbine; at the same time, hydrogen blending can effectively improve the ignition performance of the fuel, which is also very beneficial to the performance of the gas turbine under extreme operating conditions; increasing the proportion of hydrogen in the fuel can make the flame structure more compact, and thus the combustion process will be more stable; carbon oxide emissions are significantly reduced after hydrogen blending.

[0003] However, due to the active chemical properties of hydrogen, the combustion process of hydrogen-rich fuel is very prone to backfire and self-ignition. Although hydrogen-rich fuel has high stability under lean burn conditions, the hydrogen blending ratio needs to reach a certain amount to have a significant effect. The combustion process of hydrogen-rich fuel is easily affected by thermoacoustic instability and thus produces oscillations. At the same time, since hydrogen has a higher flame temperature, increasing the hydrogen blending ratio of the fuel will nonlinearly increase NO x emission. Summary of the Invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a hydrogen injection system and flame stabilization method for a gas turbine. By injecting a small amount of hydrogen, it is possible to further expand the lean burn limit of combustion while stabilizing the flame, improve the fuel ignition performance and combustion efficiency, and reduce the risks of backfire, auto-ignition, thermoacoustic oscillation during the combustion process, as well as the emission of pollutants such as carbon oxides.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is:

[0006] A hydrogen injection system for a gas turbine includes a hydrogen storage tank 9 , which is connected to a hydrogen injector via a pipeline with a gas mass flow meter to directly inject hydrogen into a combustion chamber 23 at a set flow rate.

[0007] The combustion chamber 23 is connected to the natural gas storage tank 10 and uses natural gas and hydrogen as fuel. In terms of volume percentage, the hydrogen directly injected into the combustion chamber 23 accounts for 1%-5% of the total fuel.

[0008] The outlet of the natural gas storage tank 10 is connected to the first interface of the third three-way joint 31 through a pipeline with a second pressure reducing valve 12, a first ball valve 13, a first gas mass flowmeter 14, a sixth ball valve 33, and a backfire preventer 32 in sequence. The second interface of the third three-way joint 31 is connected to the air supply system, and the third interface is connected to the first interface of the second three-way joint 29. The second and third interfaces of the second three-way joint 29 are both connected to the gas nozzle 27.

[0009] The air supply system includes a compressor 1, and the outlet of the compressor 1 is connected to the second interface of the third three-way joint 31 through a pipeline with a pre-pressure stabilizing tank 2, a pre-filter 3, a freeze dryer 4, a precision filter 5, an ultra-precision filter 6, a post-pressure stabilizing tank 7, a seventh ball valve 34, a fourth gas mass flowmeter 36 and an eighth ball valve 35 in sequence.

[0010] The gas nozzle 27 is disposed at the bottom of the combustion chamber 23 , and the nozzle of the second hydrogen injector 28 is close to the nozzle of the gas nozzle 27 .

[0011] There are two hydrogen injectors, namely a first hydrogen injector 19 with a nozzle located at the lower position of the side wall of the combustion chamber 23 and a second hydrogen injector 28 with a nozzle located at the bottom of the combustion chamber 23. The outlet of the hydrogen storage tank 9 is connected to the first interface of the first three-way joint 16, the second interface of the first three-way joint 16 is connected to the first hydrogen injector 19 through a pipeline with a third ball valve 17, a second gas mass flowmeter 18 and a fourth ball valve 20 in sequence, and the third interface of the first three-way joint 16 is connected to the second hydrogen injector 28 through a pipeline with a second ball valve 15, a third gas mass flowmeter 21 and a fifth ball valve 30 in sequence.

[0012] A first pressure reducing valve 11 is provided at the outlet of the hydrogen storage tank 9 to adjust the pressure of the hydrogen flowing out of the hydrogen storage tank 9 to a required pressure.

[0013] The present invention also provides a flame stabilization method using the hydrogen injection system of the gas turbine, wherein air and fuel are metered separately and then mixed and sent into the combustion chamber 23, and then hydrogen is metered and directly injected into the combustion chamber 23 at a set flow rate for ignition and combustion.

[0014] The fuel is natural gas and hydrogen, the volume percentage of the hydrogen is 1%-5%, the volume percentage of the natural gas is 99%-95%, and the sum of the volume percentages of hydrogen and natural gas is 100%.

[0015] The air and natural gas are premixed in a lean-burn manner and enter the combustion chamber through the gas nozzle 27 to limit NOx emissions.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] This invention abandons the traditional premixing of hydrogen and fuel prior to combustion in a gas turbine. Instead, it utilizes a non-premixed combustion method. The volumetric flow rates of hydrogen, natural gas, and air are precisely measured and controlled using a gas mass flowmeter. Hydrogen is injected into the combustion chamber using two methods: one method injects a small amount of hydrogen directly from the combustion chamber head for combustion, and the other method injects hydrogen from the combustion chamber sidewall for combustion. Experiments have shown that when hydrogen and fuel are burned non-premixed, only a 2% hydrogen volume fraction is required to achieve excellent flame stabilization. Compared to hydrogen-blended fuels with the same hydrogen content, the flame structure remains unchanged and the method effectively broadens the engine's operating envelope, improves fuel ignition performance and combustion efficiency, and further reduces carbon oxide emissions. Because this flame stabilization method requires a very low hydrogen volume fraction, flashback, autoignition, and thermoacoustic instability are minimized. The air and natural gas are burned in a premixed, lean-burn method, further limiting NOx emissions. The final optimized volume fraction of direct injection hydrogen is 1%-5%, and the best volume fraction of direct injection hydrogen is 4%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention relates to a hydrogen injection system for a gas turbine.

[0019] Figure 2 The present invention provides a gas supply system and a measurement and control system including a hydrogen injection system.

[0020] Figure 3 Macroscopic structure of the flame when hydrogen with a volume fraction ZH2 = 2% is directly injected from the head of the combustion chamber when the equivalence ratio F = 0.5 and the flow velocity U = 15m / s.

[0021] Figure 4 This is the flame macrostructure diagram of hydrogen-doped natural gas with an equivalence ratio of F=0.5, a flow velocity of U=15m / s, and a volume fraction of ZH2=2%.

[0022] Figure 5 When the equivalence ratio F=0.7 and the flow velocity U=15m / s, the relationship between CO emissions and the hydrogen gas volume fraction of direct injection hydrogen and hydrogen-blended natural gas is shown.

[0023] Figure 6 For an equivalence ratio of F = 0.7 and a flow velocity of U = 15 m / s, the relationship between NOx emissions and the hydrogen gas volume fraction of direct injection hydrogen and hydrogen-blended natural gas is shown.

[0024] Figure 7 Comparison of the effects of direct injection of hydrogen with a volume fraction of ZH2 = 2% and hydrogen-blended natural gas on the flame blowout limit.

[0025] Figure 8 The figure compares the effects of direct injection of hydrogen with a volume fraction of ZH2 = 2% and hydrogen-blended natural gas on the flame ignition performance.

[0026] Figure 1 and Figure 2 1 is a compressor, 2 is a pre-surge tank, 3 is a pre-filter, 4 is a freeze dryer, 5 is a precision filter, 6 is an ultra-precision filter, 7 is a post-surge tank, 8 is an oil-water separator, 9 is a hydrogen storage tank, 10 is a natural gas storage tank, 11 is a first pressure reducing valve, 12 is a second pressure reducing valve, 13 is a first ball valve, 14 is a first gas mass flow meter, 15 is a second ball valve, 16 is a first three-way joint, 17 is a third ball valve, 18 is a second gas mass flow meter, 19 is a first hydrogen injector, 20 is a second Four ball valves, 21 is the third gas mass flow meter, 22 is a camera, 23 is a combustion chamber, 24 is a sampling probe, 25 is an ignition nozzle, 26 is a Fourier transform infrared spectrometer gas analyzer, 27 is a gas nozzle, 28 is a second hydrogen injector, 29 is a second three-way joint, 30 is a fifth ball valve, 31 is a third three-way joint, 32 is a backfire preventer, 33 is a sixth ball valve, 34 is a seventh ball valve, 35 is an eighth ball valve, 36 is a fourth gas mass flow meter, 37 is a computer, 38 is a host, and 39 is an intake end wall. DETAILED DESCRIPTION

[0027] The embodiments of the present invention are described in detail below with reference to the accompanying drawings and examples.

[0028] The present invention provides a hydrogen injection system for a gas turbine. Hydrogen is not mixed with the natural gas or air premix. Instead, it is injected directly into the combustion chamber from the top or sidewalls. Based on the set lean-burn operating conditions, the flow rates of natural gas, air, and hydrogen are precisely measured and controlled via a gas mass flowmeter.

[0029] like Figure 1 As shown, the present invention includes a hydrogen storage tank 9, which is connected to a hydrogen injector (whose nozzle diameter can be as fine as a pinhole) via a pipeline with a gas mass flowmeter. This injects hydrogen directly into the combustion chamber 23 at a set flow rate. As an optimization, a first pressure reducing valve 11 can be provided at the outlet of the hydrogen storage tank 9 to regulate the pressure of the hydrogen flowing out of the hydrogen storage tank 9 to a desired level.

[0030] refer to Figure 2 In a specific embodiment of the present invention, there are two hydrogen injectors: a first hydrogen injector 19 having a nozzle located at the lower portion of the sidewall of the combustion chamber 23, and a second hydrogen injector 28 having a nozzle located at the bottom portion of the combustion chamber 23. The outlet of the hydrogen storage tank 9 is connected to port 1 of the first three-way joint 16. Port 2 of the first three-way joint 16 is connected to the first hydrogen injector 19 via a pipeline sequentially provided with a third ball valve 17, a second gas mass flowmeter 18, and a fourth ball valve 20. Port 3 of the first three-way joint 16 is connected to the second hydrogen injector 28 via a pipeline sequentially provided with a second ball valve 15, a third gas mass flowmeter 21, and a fifth ball valve 30. When the gas turbine of the present invention is operating, hydrogen can be directly injected into the combustion chamber 23 from only one of the branches, and either branch can be selected during operation. When hydrogen is selected to be injected from the bottom of the combustion chamber 23, the third ball valve 17, the fourth ball valve 20 and the second gas mass flowmeter 18 are closed, and the second ball valve 15, the fifth ball valve 30 and the third gas mass flowmeter 21 are opened; when hydrogen is selected to be injected from the side wall of the combustion chamber 23, the second ball valve 15, the fifth ball valve 30 and the third gas mass flowmeter 21 are closed, and the third ball valve 17, the fourth ball valve 20 and the second gas mass flowmeter 18 are opened.

[0031] In a specific embodiment of the present invention, the right side of the first hydrogen injector 19 is flush with the outer wall of the intake end wall 39 of the combustion chamber 23; the nozzle of the first hydrogen injector 19 is flush with the inner side of the side wall of the combustion chamber 23. The second hydrogen injector 28 and the gas nozzle 27 are coaxially connected to the combustion chamber 23; the nozzles of the second hydrogen injector 28 and the gas nozzle 27 are both flush with the inner wall of the intake end wall 39 of the combustion chamber 23.

[0032] The fuel of the present invention adopts natural gas and hydrogen, so the system should also include a natural gas supply system and a conventional air supply system. Figure 2 The natural gas supply system primarily includes a natural gas storage tank 10. The outlet of the natural gas storage tank 10 is connected to port 1 of a third three-way joint 31 via a pipeline that includes, in sequence, a second pressure reducing valve 12, a first ball valve 13, a first gas mass flowmeter 14, a sixth ball valve 33, and a backfire preventer 32. Port 2 of the third three-way joint 31 is connected to the air supply system, and port 3 is connected to port 1 of a second three-way joint 29. Both ports 2 and 3 of the second three-way joint 29 are connected to a gas nozzle 27. The gas nozzle 27 is located at the bottom of the combustion chamber 23, with the nozzle of the hydrogen injector close to the nozzle of the gas nozzle 27. The combustion chamber 23 is also connected to an ignition nozzle 25 for ignition.

[0033] Also refer to Figure 2The air supply system includes a compressor 1. The outlet of compressor 1 is connected to port 2 of a third three-way joint 31 via a pipeline that includes a pre-surge tank 2, a pre-filter 3, a freeze dryer 4, a precision filter 5, an ultra-precision filter 6, a post-surge tank 7, a seventh ball valve 34, a fourth gas mass flow meter 36, and an eighth ball valve 35. An oil-water separator 8 may also be provided.

[0034] To facilitate observation, control, and analysis, the present invention also includes a camera 22, a sampling probe 24, a Fourier transform infrared spectroscopy gas analyzer 26, a computer 37, and a host computer 38. The camera 22 obtains the macroscopic structure of the flame; the sampling probe 24, the Fourier transform infrared spectroscopy gas analyzer 26, the computer 37, and the host computer 38 obtain the emissions of carbon oxides and nitrogen oxides during the flame combustion process. Thus, the first ball valve 13, the first gas mass flowmeter 14, the second ball valve 15, the third ball valve 17, the second gas mass flowmeter 18, the fourth ball valve 20, the third gas mass flowmeter 21, the fifth ball valve 30, the sixth ball valve 33, the seventh ball valve 34, the fourth gas mass flowmeter 36, the eighth ball valve 35, the camera 22, the sampling probe 24, the Fourier transform infrared spectroscopy gas analyzer 26, the computer 37, and the host computer 38 constitute the measurement and control system of the present invention.

[0035] Based on the hydrogen injection system, the present invention provides a corresponding flame stabilization method: natural gas and hydrogen adopt a non-premixed combustion mode, first the air and fuel natural gas are separately metered and then mixed and sent into the combustion chamber 23, then the hydrogen is metered and directly injected into the combustion chamber 23 at a set flow rate (directly injected from the intake end wall 39 of the gas turbine combustion chamber 23, or injected from the side wall of the combustion chamber 23), and ignited and burned.

[0036] In the present invention, the volume percentage of hydrogen is 1%-5%, the volume percentage of natural gas is 99%-95%, and the total volume percentage of hydrogen and natural gas is 100%. The amount of air injected is calculated based on a given equivalence ratio. For example, in the patent, when the equivalence ratio is 0.7 and the volume percentage of hydrogen is 3% (3% of the total volume of hydrogen and natural gas), the calculated volume fraction of natural gas is 6.78%, the volume fraction of hydrogen is 0.21%, and the volume fraction of air is 93.01%, and the total volume fraction of the three is 100%.

[0037] The optimized volume fraction of direct injection hydrogen is 1%-5%, and the best volume fraction is 4%.

[0038] More specific steps are as follows:

[0039] 1. Air is supplied by compressor 1, stored and pressure-stabilized by pre-surge tank 2, removed by pre-filter 3 for dust and impurities, then dehumidified by freeze dryer 4 for moisture removal. A precision filter 5 removes oil particles, and an ultra-precision filter 6 further removes impurities. A post-surge tank 7 further stabilizes the pressure. The natural gas volume flow is then measured and controlled by seventh ball valve 34 and fourth gas mass flowmeter 36. The natural gas is then mixed with the natural gas by eighth ball valve 35 and third tee 31, then enters the combustion chamber through second tee 29 and gas nozzle 27. Furthermore, an oil-water separator 8 collects the sediment in pre-surge tank 2, impurities, oil, and other waste removed by pre-filter 3, precision filter 5, and ultra-precision filter 6, and the moisture removed by freeze dryer 4.

[0040] 2. Using natural gas as one of the fuels, part of the natural gas is brought from the natural gas storage tank 10 to the required pressure through the second pressure reducing valve 12, the natural gas flow is controlled by the first ball valve 13, the natural gas volume flow is measured by the first gas mass flowmeter 14, and then the natural gas is mixed with air through the sixth ball valve 33, the backfire preventer 32 and the third three-way joint 31, and then enters the combustion chamber through the second three-way joint 29 and the gas nozzle 27.

[0041] 3. A small amount of hydrogen flows from the hydrogen storage tank 9 and is split into two paths through the first pressure reducing valve 11 and the first three-way connector 16. One path is injected directly into the combustion chamber 23 through the sidewall via the third ball valve 17, the second gas mass flow meter 18, the fourth ball valve 20, and the first hydrogen injector 19. The other path is injected directly into the combustion chamber 23 through the second ball valve 15, the third gas mass flow meter 21, the fifth ball valve 30, and the second hydrogen injector 28. During gas turbine operation, hydrogen is directly injected into the combustion chamber through only one of the two paths. This means that the natural gas and air are completely premixed before entering the combustion chamber 23, while the hydrogen is injected directly into the combustion chamber without premixing.

[0042] 4. Ignition nozzle 25 ignites the gas, causing it to burn. During this process, camera 22 captures the flame's position and shape, comparing it to the shape of the hydrogen-blended fuel combustion flame to analyze the flame stabilization effect of direct hydrogen injection. Carbon oxide and NOx emissions are measured using sampling probe 24 and Fourier transform infrared spectrometer gas analyzer 26 to analyze the impact of direct hydrogen injection on CO and NOx emissions.

[0043] In a specific embodiment of the present invention, air and natural gas can be introduced into the combustion chamber via gas nozzle 27 in a lean premixed manner to limit NOx emissions. By directly injecting hydrogen into the combustion chamber, the present invention improves flame combustion stability, further extends the lean burn limit of combustion, enhances fuel ignition performance and thermal efficiency, reduces the risk of spontaneous combustion, flashback, autoignition, and thermoacoustic oscillation during the combustion of hydrogen-rich fuels, and limits the emission of pollutants such as nitrogen oxides.

[0044] Figure 3 The macroscopic structure of the flame when the equivalence ratio F = 0.5, the flow velocity U = 15m / s, and the volume fraction ZH2 = 2% of hydrogen are directly injected from the head of the combustion chamber. Figure 4 The macroscopic structure of the hydrogen-blended natural gas flame with the same equivalence ratio and flow rate and the same hydrogen volume fraction shows that the flame of the direct hydrogen injection burns more stably at the head of the combustion chamber than the hydrogen-blended natural gas flame. The hydrogen-blended natural gas flame appears to be rising and is close to being blown out. Therefore, the hydrogen and natural gas are not mixed. The method of directly injecting a small amount of hydrogen can achieve a good flame stabilization effect.

[0045] Figure 5 The figure shows the relationship between CO emissions and the hydrogen volume fraction of direct hydrogen injection and hydrogen-blended natural gas, for an equivalence ratio F = 0.7 and a flow rate U = 15 m / s. The figure shows that direct hydrogen injection effectively reduces CO emissions, and CO emissions decrease as the direct hydrogen injection volume fraction increases. At ZH2 = 4%, CO emissions are significantly reduced, while at ZH2 = 5%, the reduction is not significant. Comparing hydrogen-blended natural gas flames with the same hydrogen volume shows that the hydrogen-blended natural gas flame does not significantly reduce CO emissions.

[0046] Figure 6 For an equivalence ratio F = 0.7 and a flow rate U = 15 m / s, the relationship between NOx emissions and the hydrogen volume fraction of direct hydrogen injection and hydrogen-blended natural gas is shown. The figure shows that at the same hydrogen volume fraction, direct hydrogen injection produces higher NOx emissions than hydrogen-blended natural gas, and when the hydrogen volume fraction is between 1% and 4%, the difference in NOx emissions between the two is not significant. However, when ZH2 exceeds 5%, NOx emissions from direct hydrogen injection rise sharply. Therefore, the optimized volume fraction of direct hydrogen injection should be between 1% and 5%, with the optimal volume fraction being 4%. At this volume fraction, flame stability is good, CO emissions are low, and NOx emissions do not increase significantly. Further optimization of NOx emissions from direct hydrogen injection is required.

[0047] Figure 7This figure compares the effects of direct hydrogen injection (ZH2) at a volume fraction of 2% and hydrogen-blended natural gas on the flame blowout limit. The figure shows that, compared to hydrogen-blended natural gas, direct hydrogen injection can further extend the lean burn limit, effectively broadening the engine's operating envelope and helping to limit NOx emissions.

[0048] Figure 8 The figure compares the effects of direct hydrogen injection (ZH2) at a volume fraction of 2% and hydrogen-blended natural gas on flame ignition performance. As can be seen from the figure, direct hydrogen injection can further improve flame ignition performance compared to hydrogen-blended natural gas.

[0049] In addition, since the direct injection of hydrogen is premixed with natural gas and air under lean-burn conditions, the amount of hydrogen injected is small, and a hydrogen injector is used, the probability of flashback and auto-ignition is reduced; during the experiment, the flame combustion is stable, the occurrence of oscillating combustion is reduced, and the combustion thermal efficiency is improved.

[0050] The above is the experimental effect produced by the first embodiment, and a detailed analysis has been conducted on it. The experimental effect produced by the second embodiment is similar to that of the first embodiment, so it will not be repeated here.

[0051] In summary, the present invention abandons the traditional method of mixing hydrogen with fuel before combustion in a gas turbine. Instead, the fuel and hydrogen are not mixed, and an appropriate hydrogen volume fraction is selected. One method is to inject a small amount of hydrogen directly into the combustion chamber from the head of the gas turbine combustion chamber for combustion, while another method is to inject it from the side wall of the combustion chamber for combustion. The natural gas and air premixed flame burns simultaneously with the hydrogen in the combustion chamber under lean burn conditions. Experiments have shown that a good flame stabilization effect can be achieved when the hydrogen volume fraction ZH2 = 2%, where ZH2 = X H2 / ( X H2 + X CH4) × 100%, X represents the mole fraction. Compared to hydrogen-blended fuels with the same hydrogen content, this fuel extends the lean burn limit, improves ignition performance, creates a more compact and stable flame structure, significantly reduces carbon oxide emissions, and mitigates thermoacoustic instability and auto-ignition. Because the injected hydrogen volume is small and premixed with natural gas and air to create a lean-burn flame, NOx emissions are limited. Furthermore, the use of a hydrogen injector significantly reduces the potential for flashback.

[0052] The above are only preferred embodiments of the present invention, but the scope of protection of the present invention is not limited to this. Any person familiar with the technology can understand and think of any changes or replacements within the technical scope disclosed by the present invention, which should be included in the scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A hydrogen injection system for a gas turbine, comprising a hydrogen storage tank (9), characterized in that: The hydrogen storage tank (9) is connected to a hydrogen injector via a pipeline with a gas mass flow meter, and hydrogen is directly injected into the combustion chamber (23) at a set flow rate. The combustion chamber (23) is connected to a natural gas storage tank (10), and natural gas and hydrogen are used as fuel. In terms of volume percentage, the hydrogen directly injected into the combustion chamber (23) accounts for 1% to 4% of the total fuel volume. The outlet of the natural gas storage tank (10) is connected to the first interface of the third three-way joint (31) through a pipeline having a second pressure reducing valve (12), a first ball valve (13), a first gas mass flow meter (14), a sixth ball valve (33), and a backfire preventer (32) in sequence; the second interface of the third three-way joint (31) is connected to the air supply system; the third interface is connected to the first interface of the second three-way joint (29); and the second and third interfaces of the second three-way joint (29) are both connected to the gas nozzle (27); There are two hydrogen injectors, namely a first hydrogen injector (19) having a nozzle located at the lower part of the side wall of the combustion chamber (23) and a second hydrogen injector (28) having a nozzle located at the bottom of the combustion chamber (23), wherein the outlet of the hydrogen storage tank (9) is connected to the first interface of the first three-way joint (16), the second interface of the first three-way joint (16) is connected to the first hydrogen injector (19) through a pipeline having a third ball valve (17), a second gas mass flow meter (18) and a fourth ball valve (20) in sequence, and the third interface of the first three-way joint (16) is connected to the second hydrogen injector (28) through a pipeline having a second ball valve (15), a third gas mass flow meter (21) and a fifth ball valve (30) in sequence; The air supply system comprises a compressor (1), the outlet of the compressor (1) is connected to the second interface of the third three-way joint (31) through a pipeline having a pre-pressure stabilizing tank (2), a pre-filter (3), a freeze dryer (4), a precision filter (5), an ultra-precision filter (6), a post-pressure stabilizing tank (7), a seventh ball valve (34), a fourth gas mass flow meter (36) and an eighth ball valve (35) in sequence; The gas nozzle (27) is arranged at the bottom of the combustion chamber (23), and the nozzle of the second hydrogen injector (28) is close to the nozzle of the gas nozzle (27).

2. The hydrogen injection system for a gas turbine according to claim 1, characterized in that: A first pressure reducing valve (11) is provided at the outlet of the hydrogen storage tank (9) to adjust the pressure of the hydrogen coming out of the hydrogen storage tank (9) to a required pressure.

3. A flame stabilization method using the hydrogen injection system of the gas turbine according to claim 1, characterized in that: Air and fuel are measured separately and then mixed and sent into a combustion chamber (23), and then hydrogen is measured and directly injected into the combustion chamber (23) at a set flow rate, and ignited and burned; the fuel is natural gas and hydrogen, the volume percentage of hydrogen in the fuel is 1%-4%, the volume percentage of natural gas is 99%-96%, and the sum of the volume percentages of hydrogen and natural gas is 100%; When the volume proportion of hydrogen is 4%, CO emissions are reduced by more than 40% and the NOx increase is less than 3%.

4. The flame stabilization method according to claim 3, characterized in that: The air and natural gas are premixed in a lean-burn manner and enter the combustion chamber through the gas nozzle (27) to limit NOx emissions.

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