A multi-mode methanol swirl burner

Abstract

The present application relates to gas turbine combustion technology field, specifically disclose a kind of multi-mode methanol swirl burner, mainly including main combustion stage sleeve, duty stage sleeve, main combustion stage swirler, duty stage swirler, main combustion stage methanol reformer, duty stage methanol reformer, duty stage nozzle etc..The burner of the present application has three working modes: methanol liquid mist, methanol steam and methanol reforming.In ignition starting phase, duty stage nozzle sprays liquid methanol, forms methanol liquid mist, realizes reliable ignition and combustion;Under partial load condition, duty stage and main combustion stage spray methanol steam that has absorbed exhaust waste heat, improve gas turbine thermal efficiency;Under full load condition, methanol is reformed into hydrogen-rich reforming gas in burner, into combustion chamber and burns, further improve thermal efficiency and reduce unconventional pollutant emissions.The multi-mode methanol swirl burner of the present application can meet the flexible combustion demand under different conditions, improve gas turbine thermal efficiency and reduce pollutant emissions.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas turbine combustion technology, in particular to a multi-mode methanol swirl burner. BACKGROUND

[0002] According to the prediction of the International Energy Agency, the global energy structure will undergo major changes under the carbon neutral scenario, with 70% of high proportion of renewable energy connected to the new power system. With the increase of renewable energy generation, the security challenges of power supply and the demand for power balance will also increase. The volatility and randomness of wind and solar power generation make the power system lack the ability to support extreme conditions. The instability of renewable energy represented by wind and solar energy leads to the increasingly prominent problem of "abandoned wind and light". In the first quarter of 2024, the abandoned light and wind rates in China were 4% and 3.9% respectively, an increase of 2% and 0.7% respectively, with a loss of about 2 billion yuan in output value. Large-scale consumption of renewable energy has become a bottleneck problem in energy structure transformation.

[0003] The preparation of green fuels such as methanol provides an effective way for large-scale consumption of renewable energy and long-term energy storage. By electrolyzing water to produce hydrogen through renewable energy, coupled with carbon dioxide capture and conversion technology, green methanol can be catalytically synthesized. Green methanol has significant advantages in energy conversion and storage and transportation, with transportation costs only 2.3% to 8.4% of hydrogen, good storage and transportation safety, and mature preparation process, so it is considered a low-cost, long-term energy storage green electricity consumption good carrier.

[0004] However, as a low-boiling-point, low-flash-point, high-vaporization-potential liquid fuel, methanol has risks of backfire, flameout, and local ablation when applied to gas turbines. Most of the swirl burners on the market are mainly suitable for fuels such as methane (such as Chinese patent application CN108844063A), hydrogen (such as Chinese patent application CN117028989A), and ammonia (such as Chinese patent application CN118687148A), and there is no swirl burner suitable for methanol gas turbine combustion. Based on the actual engineering needs, the present application designs a multi-mode methanol swirl burner that can automatically switch between methanol liquid mist, methanol vapor, and methanol reforming modes according to the operating state of the burner, effectively utilizes the waste heat of the burner to improve the thermal efficiency of the gas turbine, and reduces pollutant emissions. SUMMARY

[0005] The present application discloses a multi-mode methanol swirl burner, which adopts a radial staged combustion organization method and is composed of a center duty stage and an outer main combustion stage. This design combines diffusion combustion and lean premixed combustion, aiming to achieve efficient combustion and low pollution emissions under different operating conditions. The duty stage is mainly responsible for flame stabilization and adopts diffusion combustion; the main combustion stage reduces NOx emissions and improves combustion efficiency through lean premixed combustion.

[0006] The main structure of the present application includes: main combustion stage sleeve, duty stage sleeve, main combustion stage swirler, duty stage swirler, main combustion stage methanol reformer, duty stage methanol reformer, main combustion stage end cooling hole, duty stage end cooling hole, main combustion stage fuel pipe, duty stage fuel pipe and duty stage nozzle. Air enters the main combustion stage and duty stage from the periphery of the main combustion stage swirler and the bottom of the burner respectively to ensure reasonable distribution of air supply.

[0007] The main combustion stage sleeve is made of a material resistant to methanol corrosion at high temperature, preferably stainless steel or other corrosion-resistant alloy. The bottom of the sleeve is connected to the top of the main combustion stage swirler, and the top flow passage is tapered with a contraction angle of 20°-40° with respect to the axis to accelerate airflow and prevent backfire. The main combustion stage sleeve has a main combustion stage end cooling hole with a diameter of 0.5mm-2.5mm and an inclination angle of 10°-30° with respect to the axis to cool the end of the main combustion stage sleeve and prevent ablation.

[0008] The duty stage sleeve is made of a material resistant to methanol corrosion at high temperature, preferably stainless steel or other corrosion-resistant alloy. The bottom of the sleeve is connected to the bottom of the main combustion stage swirler, and the top flow passage is tapered with a contraction angle of 20°-40° with respect to the axis to accelerate airflow and assist methanol atomization. The duty stage sleeve has a duty stage end cooling hole with a diameter of 0.5mm-2.5mm and an inclination angle of 10°-30° with respect to the axis to cool the end of the duty stage sleeve and prevent ablation.

[0009] The main combustion stage swirler is preferably a radial swirler, and can also be an axial swirler. The structure of the main combustion stage swirler includes swirler vanes, injection holes and a fuel cavity. The top of the main combustion stage swirler is connected to the main combustion stage sleeve, and the bottom is connected to the duty stage sleeve. The bottom of the main combustion stage swirler is connected to 1-8 main combustion stage fuel pipes, and the main combustion stage swirler has an annular cavity, i.e. a fuel cavity. The bottom of the fuel cavity is equipped with a main combustion stage methanol reformer, which can reform methanol into hydrogen-rich reforming gas under high temperature conditions. The swirler passage has injection holes with a diameter of 0.5mm-5mm, and the number of injection holes is 6-24. The fuel is injected from the injection holes and fully mixed with high-speed air in the swirler passage. The installation angle of the swirler vanes is 30°-70°, and the swirl number is 0.5-1. There are 6-16 swirler vanes evenly distributed in the circumferential direction. By reasonably designing the swirl number, stable, efficient and low-pollution combustion of the burner under high load can be achieved.

[0010] The duty stage swirler is preferably an axial swirler, and can also be a radial swirler. The duty stage swirler has 6-16 swirler vanes with a thickness of 0.5mm-5mm and a height of 10mm-50mm, and the swirl number is 0.5-1. By reasonably designing the swirl number, the atomization effect of liquid methanol can be strengthened, and reliable ignition and stable combustion of the burner under low load can be achieved.

[0011] The on-duty class fuel pipeline is connected with an on-duty class nozzle; the on-duty class nozzle is distributed with injection holes with a diameter of 0.5mm-5mm, 6-16 of which are evenly distributed in the circumferential direction; the fuel injection direction of the on-duty class nozzle forms an angle of 45°-70° with the axis; and a methanol reformer is arranged in the middle of the on-duty class fuel pipeline, which can reform the methanol steam into rich hydrogen reforming gas under high temperature conditions.

[0012] The working principle of the present application is as follows:

[0013] The multi-mode methanol rotating flow combustor of the present application can automatically switch among three combustion modes of methanol liquid mist, methanol steam and methanol reforming according to different operating conditions. In the present application, the liquid methanol is gradually heated to be gaseous by absorbing the exhaust heat when passing through the heat exchanger, and with the further improvement of the operating condition of the gas turbine, the methanol steam is heated to the required temperature for self-heating reforming, and the working mode of the combustor is determined by the operating condition of the gas turbine and the temperature of the methanol at the inlet of the combustor.

[0014] When the combustor is in the ignition starting stage, the exhaust heat is less, and the methanol remains liquid. At this time, the combustor is in the methanol liquid mist mode, the on-duty class nozzle sprays the methanol liquid mist into the combustion chamber, and the main combustion stage is not started. The on-duty class adopts diffusion combustion mode to ensure stable flame and complete ignition smoothly.

[0015] When the combustor enters the part load operation, the exhaust heat gradually increases, the liquid methanol is heated to be gaseous by passing through the heat exchanger, and the combustor enters mode II (methanol steam mode). In this mode, the main combustion stage and the on-duty class are both supplied with methanol steam, forming a methanol steam rotating flow flame in the combustion chamber, which ensures uniform and stable combustion, improves the thermal efficiency of the gas turbine, and reduces the emission of conventional pollutants such as NOx.

[0016] Under full load condition, the methanol steam is further heated and reaches the required temperature for self-heating reforming, at which time the combustor enters mode III (methanol reforming mode). In this mode, the methanol steam in the main combustion stage and the on-duty class is converted into rich hydrogen reforming gas by the methanol reformer and sprayed into the combustion chamber for combustion. The rich hydrogen reforming gas can significantly reduce the emission of unconventional pollutants such as formaldehyde, and further improve the thermal efficiency of the gas turbine. The reforming mode can effectively utilize the waste heat of the exhaust gas of the gas turbine, and is particularly suitable for the continuous operation of the combustor under high load.

[0017] The combustor of the present application can automatically switch among three working modes according to the temperature of the methanol at the inlet of the combustor. The methanol first enters the heat exchanger in liquid state to absorb the exhaust heat; with the increase of the exhaust temperature, the methanol gradually changes to be gaseous, enters mode II; under full load condition, the methanol is further heated and converted into rich hydrogen reforming gas by the reformer, and enters mode III. This switching process does not require manual operation and can be automatically completed according to the operating state of the gas turbine, ensuring the efficient and stable operation of the combustor under different load conditions.

[0018] The present application has the following advantages compared with the prior art:

[0019] (1) Coupling of the structure design of the methanol reforming swirler burner

[0020] The present application integrates a small methanol reformer in the main combustion stage and the duty stage channel of the swirler burner. When the methanol at the inlet of the burner reaches a certain temperature, the methanol undergoes a reforming reaction in the burner to generate hydrogen-rich reforming gas. This structure realizes efficient reforming of methanol under limited space conditions.

[0021] (2) Multi-mode combustion flexibility and high thermal efficiency

[0022] The present application combines three combustion modes of methanol liquid mist, methanol vapor and methanol reforming, and can flexibly switch the combustion mode according to different operating stages (ignition start, partial load, full load) of the gas turbine. This design not only meets the needs of the burner under different load conditions, but also improves the thermal efficiency of the gas turbine by efficiently utilizing the exhaust heat in the combustion process, so that the gas turbine can maintain high efficiency under various operating conditions.

[0023] (3) Reducing pollutant emissions

[0024] The present application adopts a radial staged combustion mode combining diffusion combustion in the duty stage and lean premixed combustion in the main combustion stage, and realizes low pollutant emissions under different operating conditions through flexible combustion mode conversion. The use of lean premixed combustion significantly reduces the emissions of conventional pollutants such as NOx and CO, and the methanol reforming mode further utilizes the combustion characteristics of hydrogen-rich gas to reduce the emissions of unconventional pollutants such as formaldehyde. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a structural schematic diagram of a multi-mode methanol swirler burner of the present application;

[0026] Figure 2 is a schematic diagram of the main combustion stage swirler of the present application;

[0027] Figure 3 is a schematic diagram of the internal flow channel of a multi-mode methanol swirler burner of the present application;

[0028] Figure 4 is a schematic diagram of multi-mode combustion of the present application;

[0029] Figure 5 is a schematic diagram of a methanol gas turbine system of the present application;

[0030] Figure 6 is a schematic diagram of a methanol gas turbine system with a carbon capture device of the present application;

[0031] In the figure: 1, main combustion stage sleeve; 2, duty stage sleeve, 3, duty stage nozzle; 4, main combustion stage swirler; 4-1, swirler blade; 4-2, injection hole; 4-3, fuel cavity, 5, main combustion stage fuel pipeline; 6, main combustion stage methanol reformer; 7, duty stage methanol reformer; 8, duty stage swirler; 9, duty stage fuel pipeline; 10, duty stage end cooling hole; 11, main combustion stage end cooling hole. DETAILED DESCRIPTION

[0032] Example 1

[0033] This embodiment describes the application of a multi-mode methanol swirled combustor in a gas turbine. The combustor is designed with three combustion modes, which can automatically switch to the appropriate mode according to the load state of the gas turbine and the temperature of the methanol at the inlet of the combustor, in order to improve the thermal efficiency of the gas turbine and reduce the emission of conventional and unconventional pollutants. The liquid methanol fuel absorbs exhaust waste heat through a heat exchanger to gradually achieve gasification and continuous heating until the required temperature for the reforming reaction is reached.

[0034] During the ignition start-up phase, the exhaust temperature of the gas turbine is low, and the exhaust waste heat is not enough to heat the methanol to a gaseous state. At this time, the combustor is in the methanol liquid mist mode. In this mode, the methanol is sprayed into the combustion chamber in the form of liquid mist through the duty stage nozzle. The duty stage nozzle is designed with multiple injection holes with diameters of 0.5mm-5mm, which are evenly distributed circumferentially, with an injection angle of 45°-70°, ensuring that the liquid methanol uniformly enters the combustion chamber and diffuses and burns. Diffusion combustion helps to stabilize the flame, avoiding the backfire and flameout phenomena that may occur during the ignition start-up process. Only the duty stage works during this stage, and the main combustion stage does not participate in combustion.

[0035] As the load of the gas turbine increases, the exhaust temperature gradually rises, and the liquid methanol is heated to a gaseous state. The combustor switches to the methanol vapor mode. In this mode, methanol vapor enters both the main combustion stage and the duty stage, forming a methanol vapor swirled flame in the combustion chamber. The main combustion stage swirler is preferably a radial swirler, which has swirler blades and a fuel cavity inside. Methanol vapor is sprayed out through the injection holes on the swirler channel and fully mixed with the high-speed air inside the swirler channel. The material of the main combustion stage sleeve is stainless steel or other corrosion-resistant alloys. The top flow channel is tapered, with a contraction angle of 20°-40° to the axis, and is provided with main combustion stage end cooling holes with diameters of 0.5mm-2.5mm for cooling the end of the main combustion stage sleeve to prevent ablation. In this mode, the lean premixed combustion of the main combustion stage and the diffusion combustion of the duty stage are combined, achieving higher combustion uniformity and stability, while reducing the emission of conventional pollutants such as NOx and improving the thermal efficiency of the gas turbine.

[0036] When the gas turbine reaches full load condition, the exhaust temperature further increases. The methanol vapor is further heated after passing through the heat exchanger and reaches the temperature required for the auto-thermal reforming reaction, and the combustor enters the methanol reforming mode. The bottom of the main combustion stage swirler fuel cavity and the standby stage fuel pipeline are respectively provided with combustion-supporting agent and standby stage methanol reformer, which can convert methanol vapor into hydrogen-rich reforming gas under high temperature conditions. The generated hydrogen-rich reforming gas enters the combustion chamber through the fuel pipeline and is fully combusted, thereby further improving the combustion efficiency and reducing the emission of conventional pollutants such as NOx, CO and unconventional pollutants such as formaldehyde. The methanol reforming mode fully utilizes the exhaust waste heat and is suitable for long-term and efficient operation under high load conditions.

[0037] During the entire operation process, the working mode of the combustor is automatically switched by the temperature change of the methanol at the inlet. When the methanol is heated from liquid to gas and further converted into hydrogen-rich reforming gas, the combustor completes the conversion of the combustion mode through physical and chemical processes. This temperature-based adaptive switching mechanism enables the combustor to achieve efficient and stable operation under various load conditions of the gas turbine.

[0038] Example 2

[0039] This example describes the application of an improved multi-mode methanol swirler combustor in a gas turbine. This example adds a separation membrane device to the methanol reformer for separating CO2 and hydrogen-rich reforming gas from the methanol reforming gas. The separated CO2 is pressurized and stored in a carbon storage tank, and the hydrogen-rich gas enters the combustor to participate in combustion. This design can significantly reduce carbon emissions and further enhance the environmental performance of the system, providing a solution for future low-carbon / zero-carbon power plants.

[0040] During the ignition and start-up phase of the gas turbine, the exhaust temperature is low and insufficient to heat the methanol to a gaseous state. At this time, the combustor is in the methanol liquid mist mode, and the liquid methanol is atomized into the combustion chamber through the standby stage nozzle. The diffusion combustion design of the standby stage ensures flame stability, thereby ensuring the smooth start-up of the gas turbine. The main combustion stage is not in operation at this stage, and carbon capture is not involved.

[0041] When the load of the gas turbine gradually increases, the exhaust temperature rises, and the methanol is heated to a gaseous state, the combustor enters the methanol vapor mode. In this mode, the main combustion stage methanol vapor is injected from the injection hole of the swirler channel and fully mixed with high-speed air in the swirler channel to form a uniform lean premixed combustion; the standby stage methanol vapor is injected from the standby stage nozzle and mixed with high-speed air in the combustion chamber to form a diffusion combustion. This stage does not involve carbon capture, and the exhaust waste heat of the gas turbine is utilized to improve the thermal efficiency of the gas turbine and reduce the emission of conventional pollutants such as NOx.

[0042] When the gas turbine enters full load operation state, the exhaust gas temperature is further increased, the methanol steam is heated to the required temperature of the autothermal reforming reaction through the heat exchanger, and the combustor enters the methanol reforming mode. In this mode, the high-temperature methanol steam is converted into methanol reforming gas under the action of the methanol reformer. After passing through the separation membrane, the methanol reforming gas is separated into CO2 and hydrogen-rich gas. The separated CO2 is pressurized and stored in the carbon storage tank to reduce carbon emissions; the hydrogen-rich gas enters the main combustion stage and the standby stage of the combustor, and is burned after being mixed with air. This mode improves the thermal efficiency of the gas turbine and achieves the synergistic effect of reducing pollution and carbon emission.

[0043] The carbon capture device is arranged on the basis of the original device, and carbon dioxide separation membrane device is added to realize carbon dioxide capture, which also significantly reduces carbon emissions, provides a more environmentally friendly solution for the application of green methanol in the gas turbine, and provides a solution for the construction of future low-carbon / zero-carbon power plants.

[0044] Finally, it should be noted that the above enumeration is only a few specific embodiments of the present application. Obviously, the present application is not limited to the above embodiments, and there can be many variations. All variations that can be directly derived or inferred from the content disclosed by those skilled in the art should be considered as the protection scope of the present application.

Claims

1. A multi-mode methanol swirl burner characterized by: The radial staged combustion organization mode is adopted, which is composed of a center duty stage and an outer main combustion stage; the duty stage adopts diffusion combustion for flame stabilization, and the main combustion stage adopts lean premixed combustion for reducing NOx emission; the combustor comprises a main combustion stage sleeve, a duty stage sleeve, a main combustion stage swirler, a duty stage swirler, a main combustion stage methanol reformer, a duty stage methanol reformer, a main combustion stage end cooling hole, a duty stage end cooling hole, a main combustion stage fuel pipe, a duty stage fuel pipe and a duty stage nozzle; Air enters the main combustion stage and the duty stage from the periphery of the main combustion stage swirler and the bottom of the combustor respectively; the main combustion stage fuel is sprayed out through the injection holes uniformly distributed on the fuel cavity, and the duty stage fuel is sprayed out through the duty stage nozzle; the combustor supports multi-mode combustion modes, including a methanol liquid mist mode, a methanol steam mode and a methanol reforming mode.

2. A multi-mode methanol swirl burner as claimed in claim 1, wherein: The main combustion stage sleeve is made of a material resistant to methanol corrosion at high temperature, which can be stainless steel or other corrosion-resistant alloy material; the bottom of the main combustion stage sleeve is connected with the top of the main combustion stage swirler; the top flow passage of the main combustion stage sleeve is tapered, and the included angle between the taper angle and the axis is 20°-40°, which is used for accelerating airflow to prevent backfire; the top of the main combustion stage sleeve is provided with a cooling hole with a diameter of 0.5 mm-2.5 mm and an included angle of 10°-30° with the axis, which is used for cooling the end of the main combustion stage sleeve to prevent ablation.

3. A multi-mode methanol swirl burner as claimed in claim 1, wherein: The duty stage sleeve is made of a material resistant to methanol corrosion at high temperature, which can be stainless steel or other corrosion-resistant alloy material; the bottom of the duty stage sleeve is connected with the bottom of the main combustion stage swirler; the top flow passage of the duty stage sleeve is tapered, and the included angle between the taper angle and the axis is 20°-40°, which is used for accelerating airflow to assist methanol atomization; the top of the duty stage sleeve is provided with a cooling hole with a diameter of 0.5 mm-2.5 mm and an included angle of 10°-30° with the axis, which is used for cooling the end of the duty stage sleeve to prevent ablation.

4. A multi-mode methanol spinflow burner as claimed in claim 1, characterized in that: The main combustion stage swirler can be a radial swirler or an axial swirler, and the structure comprises swirl vanes, injection holes and a fuel cavity; the top of the main combustion stage swirler is connected with the main combustion stage sleeve, and the bottom is connected with the duty stage sleeve; the main combustion stage swirler has an annular fuel cavity in the inside, and the bottom is connected with 1-8 main combustion stage fuel pipes; the bottom of the fuel cavity is provided with a main combustion stage methanol reformer, which can reform methanol into hydrogen-rich gas under high temperature conditions; the swirl passage is provided with injection holes with a diameter of 0.5 mm-5 mm, and the number is 6-24; the fuel is sprayed out from the injection holes and fully mixed with high-speed air in the swirl passage; the installation angle of the swirl vanes is 30°-70°, the swirl number is 0.5-1, and the number of the swirl vanes along the circumferential direction is 6-16.

5. A multi-mode methanol spinflow burner as claimed in claim 1, characterized in that: The duty stage swirler can be an axial swirler or a radial swirler, and has 6-16 swirl vanes with a thickness of 0.5 mm-5 mm and a height of 10 mm-50 mm along the circumferential direction, and the swirl number is 0.5-1.

6. A multi-mode methanol spinflow burner according to claim 1, wherein: The on-duty class fuel pipeline is connected with the on-duty class nozzle; the on-duty class nozzle is distributed with injection holes with a diameter of 0.5 mm-5 mm, and 6-16 holes are uniformly distributed along the circumference; the fuel injection direction of the on-duty class nozzle is at an angle of 45°-70° with the axis; and a methanol reformer is arranged in the middle of the on-duty class fuel pipeline, which can reform the methanol steam into rich hydrogen reforming gas when the methanol steam reaches a temperature of 300℃ or above.

7. The method of claim 1 wherein the multi-mode methanol swirl burner for gas turbines is characterized by: The multi-mode combustion mode includes a methanol liquid mist mode, a methanol steam mode and a methanol reforming mode, specifically: in the ignition starting stage, the on-duty class nozzle sprays liquid methanol to form a methanol liquid mist at the outlet of the combustor, which can realize reliable ignition and combustion; under a partial load condition, the on-duty class and the main combustion class jointly spray methanol steam to form a methanol steam rotating flame in the combustion chamber; under a full load condition, the methanol steam is further heated and reaches the required temperature for self-heating reforming, and is converted into rich hydrogen reforming gas after passing through the on-duty class and the main combustion class methanol reformers, and is fully combusted in the combustion chamber.

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