An ejector multi-nozzle swirl injector and its ignition method

Abstract

The present application relates to the technical field of combustion chamber injector, and particularly relates to an injection type multi-nozzle swirl injector, which comprises an injector panel, an injector shell is arranged on the upstream side of the injector panel, an air guide mechanism for separating the airflow entering the injector shell into an oxygen-rich gas flow path and an air flow path is arranged in the interior of the injector shell, the air guide mechanism comprises a flow guide cover arranged in the interior of the injector shell, and the flow guide cover separates the interior of the injector shell into a high-temperature oxygen-rich gas flow channel and a high-pressure air flow channel. The high-temperature oxygen-rich gas and the high-pressure air are physically isolated at the source of the air path by the flow guide cover, the standby nozzle works independently in the high-temperature oxygen-rich environment, even if the incoming flow velocity changes in a wide range of working conditions, the standby flame can still be stably maintained and is not easy to be blown out, and the technical problem that the wide-working-condition engine is difficult to ignite and stabilize the flame in the whole working envelope is fundamentally solved, and the self-adaptive stable flame can be realized without relying on a complex active control strategy.

Description

Technical Field

[0001] This invention relates to the field of combustion chamber injector technology, and more particularly to an ejector-type multi-nozzle swirl injector and its ignition method. Background Technology

[0002] With the continuous improvement of thrust-to-weight ratio and power density of power devices such as aero engines and gas turbines, the size of combustion chambers is increasing. Multi-nozzle injector structures are widely used because they can achieve efficient gas mixing, stable combustion and uniform heat release. However, for large-scale injection disks, the ignition energy provided by local igniters is difficult to ignite all nozzles at the same time, which can easily lead to local flameout.

[0003] Traditional step-by-step ignition schemes rely heavily on complex ignition control timing, which places extremely high demands on the reliability of the igniter and control system. In addition, the gas flow rate of a wide-condition engine varies greatly with the operating flow rate, making it difficult to ensure stable combustion throughout the entire operating envelope. When the flame propagation speed and flow speed are mismatched, flame blowout can easily occur, which seriously restricts the reliability and safety of the engine. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides an ejector-type multi-nozzle swirl injector and its ignition method, which solves the technical problems of existing step-by-step ignition schemes that rely on complex ignition timing sequences and the flame being easily blown out under wide operating conditions, leading to unstable combustion. It has the advantages of stable ignition across the entire operating range, no need for an independent cold source, compact structure, and high ignition reliability.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an ejector-type multi-nozzle swirl injector, including an injector panel, an injector housing disposed on the upstream side of the injector panel, and a gas guiding mechanism inside the injector housing for separating the gas flow entering the injector housing into an oxygen-rich gas flow path and an air flow path. The gas guiding mechanism includes a guide shroud disposed inside the injector housing, which divides the interior of the injector housing into a high-temperature oxygen-rich gas flow channel and a high-pressure air flow channel. A duty nozzle communicating with the high-temperature oxygen-rich gas flow channel is disposed inside the bottom end of the injector housing, and a flame tube is disposed between the outlet end face of the duty nozzle and the injector panel. The outlet end face of the flame tube is coplanar with the injector panel. Multiple cooling holes are provided on the wall of the flame tube to draw in air and form a cooling gas film under the action of the duty flame. Multiple main combustion nozzles are arranged around the circumference of the duty nozzle on the injector panel. The inlet of the main combustion nozzle is connected to the high-pressure air flow channel. The fuel inlets of the duty nozzle and the main combustion nozzle are connected to the fuel supply pipeline. The high-temperature oxygen-rich gas and the high-pressure air are physically isolated at the source of the gas path through the gas guiding mechanism, so that the duty nozzle works in a high-temperature oxygen-rich environment to obtain a wide range of stable flame characteristics, while the main combustion nozzle works in a high-pressure air environment to ensure the normal combustion organization of the main combustion zone. The two do not interfere with each other.

[0006] Preferably, the flow guide is a streamlined through-type structure with a cross-section that gradually narrows along the airflow direction. The inner wall of the flow guide forms a high-temperature oxygen-rich gas flow channel, and the outer wall of the flow guide forms a high-pressure air flow channel between the inner wall of the injector housing. The flow guide adopts a streamlined and narrowing design, which on the one hand can accelerate the flow of high-temperature oxygen-rich gas and reduce flow loss; on the other hand, its outer wall can naturally form an annular high-pressure air flow channel with the inner wall of the injector housing, eliminating the need for additional partition components and helping to reduce the overall size of the injector.

[0007] Preferably, the main combustion nozzle has a multi-row structure, arranged concentrically from the inside to the outside along the radial direction of the injector panel, with adjacent rows of main combustion nozzles alternately distributed in the circumferential direction. Combined with the ignition method of the duty flame spreading outward step by step, each ring of main combustion nozzles can be ignited sequentially when the duty flame spreads to the radial position.

[0008] Preferably, both the duty nozzle and the main combustion nozzle are gas swirling nozzles. The gas swirling nozzle includes a swirler, a swirling cup, a fuel channel, and a fuel nozzle arranged sequentially along the airflow direction. The fuel channel is connected to the fuel supply pipeline, and the fuel nozzle is opened on the wall of the swirling cup. After passing through the swirler, the gas will generate rotational momentum and form a high-speed swirling field in the swirling cup. After the fuel is ejected from the fuel nozzle on the wall of the swirling cup, it will be rapidly broken up and atomized under strong shearing and fully mixed with the swirling gas. After the swirling jet is ejected, it will form a recirculation zone in the flame tube or combustion chamber, which plays a role in stabilizing the flame. For both the duty nozzle and the main combustion nozzle, it can effectively broaden the operating range of stable combustion.

[0009] Preferably, the cross-sectional shape of the flame tube is either circular or wavy, the axial expansion angle of the flame tube is in the range of 0° to 10°, and the length of the flame tube along the axial direction is not greater than 200mm. The cross-sectional shape of the flame tube affects the mixing efficiency of the standby flame and the surrounding airflow. A circular cross-section is simple to process and has good flow symmetry, while a wavy cross-section can form an alternating concave and convex contour in the circumferential direction of the flame tube, increasing the contact area and mixing channel of the airflow inside and outside the flame tube, which is beneficial to the mixing of the standby high-temperature gas and the surrounding air and accelerates the staged ignition process.

[0010] Preferably, the cooling holes are evenly distributed in multiple rows along the circumference of the side wall of the flame tube. The shape of the cooling holes is at least one of circular holes, raindrop-shaped holes, or elliptical holes. The equivalent aperture of the cooling holes is not less than 2 mm to ensure sufficient cooling air flow under limited pressure difference drive. When raindrop-shaped holes are used, their cross-sectional configuration of pointed top and round bottom has the process feature of top self-forming, which is especially suitable for laser selective melting forming process and can effectively avoid the quality defect of top arc collapse during the forming process of large diameter circular holes.

[0011] Preferably, an ignition mounting hole is provided on the wall of the flame tube, and an ignition rod for igniting the mixture sprayed by the duty nozzle is inserted into the ignition mounting hole. The axis of the ignition rod is arranged at a certain angle with the axis of the injector, so that the electric spark area generated by the ignition rod can cover the mixing area of ​​fuel and high-temperature oxygen-rich gas in the flame tube, thereby ensuring the ignition success rate.

[0012] The present invention also provides an ignition method for an ejector-type multi-nozzle swirl injector, comprising the following steps: S1: High-temperature oxygen-enriched gas is introduced into the duty nozzle through the high-temperature oxygen-enriched gas flow channel via the gas guiding mechanism, and high-pressure air is introduced into each main combustion nozzle through the high-pressure air flow channel. At the same time, fuel is supplied to the duty nozzle and the main combustion nozzle through the fuel supply pipeline, so that the fuel is mixed with the high-temperature oxygen-enriched gas in the duty nozzle and mixed with the high-pressure air in the main combustion nozzle. S2: Under the constraint of the flame tube wall, the high-temperature oxygen-rich gas ejected by the duty nozzle and the swirling mixture of fuel form a recirculation zone inside the flame tube, which fully mixes the fuel and the high-temperature oxygen-rich gas and prolongs the residence time of the mixture, preparing for ignition. S3: When the ignition rod is energized, it generates an electric spark, which ignites the high-temperature oxygen-rich gas and fuel mixture inside the flame tube. Due to the fast chemical reaction rate and high flame propagation speed in the high-temperature oxygen-rich environment, it can still match the incoming flow velocity even under conditions of wide variation in flow velocity. Therefore, it is easy to ignite and has a wide flame stabilization range, forming a stable standby flame. S4: After the standby flame is formed, the high-temperature and high-speed standby flame jet creates a negative pressure zone inside the flame tube, generating an ejection effect. This causes some of the air in the high-pressure air channel to be drawn into the flame tube through the cooling holes on the flame tube wall under the pressure difference. The air then flows along the inner wall of the flame tube to form a cooling gas film, which cools and protects the flame tube wall. The air flow through the cooling holes accounts for no more than 0.5% of the total air flow, ensuring that the equivalence ratio impact on the standby flame area is minimized. S5: The duty flame spreads downstream along the flame tube and is ejected from the outlet end face of the flame tube. It first ignites the mixture of fuel and high-pressure air ejected from the main combustion nozzles closest to the duty nozzle. The ignited main combustion nozzles form a new high-temperature combustion zone. S6: The new high-temperature combustion zone expands further outward along the radial direction, igniting the remaining main combustion nozzles in stages until all main combustion nozzles are ignited, achieving stable ignition of the entire combustion chamber.

[0013] By employing the above technical solution, the present invention provides an ejector-type multi-nozzle swirl injector, which has at least the following beneficial effects: 1. This invention physically isolates the high-temperature oxygen-rich combustion gas from the high-pressure air at the gas source by using a flow guide, so that the duty nozzle can work independently in a high-temperature oxygen-rich environment. Even if the incoming flow velocity varies with a wide range of operating conditions, the duty flame can still be maintained stably and is not easily blown out. This fundamentally solves the technical problem of difficult ignition and flame stabilization of engines under wide operating conditions throughout the entire operating envelope, and can achieve adaptive flame stabilization without relying on complex active control strategies.

[0014] 2. This invention utilizes a high-temperature, high-speed jet to create a negative pressure zone inside the flame tube. Combined with the pressure difference between the high-pressure air channels outside the flame tube, high-pressure air can be automatically drawn into the flame tube through cooling holes on the flame tube wall, forming a continuous cooling gas film along the inner wall. This cooling method relies entirely on the ejection effect of the flame itself, without the need for an additional independent cooling gas source or cooling pump, thus achieving self-cooling protection of the flame tube wall.

[0015] 3. This invention utilizes the characteristic of the standby flame, which propagates outward along the surface of the injector panel after being ejected from the outlet end face of the flame tube. The standby flame first ignites the nearest ring of main combustion nozzles, and then the main combustion nozzles form a new high-temperature combustion zone and continue to expand outward, thereby igniting the remaining rings of main combustion nozzles in sequence. This effectively avoids the defect in the prior art where the energy of a single ignition source is insufficient to ignite all nozzles at the same time, and significantly improves the ignition reliability of large-scale multi-nozzle combustion chambers.

[0016] 4. The flow guide of the present invention adopts a streamlined through-type structure with a cross-section that gradually shrinks along the airflow direction. Its inner wall surface encloses and forms a high-temperature oxygen-rich gas flow channel for use by the duty nozzle. The outer wall surface and the inner wall surface of the injector housing naturally form an annular high-pressure air flow channel for use by the main combustion nozzle. This integrated design can simultaneously complete the functions of flow diversion, flow guidance and sealing without the need for additional partition components, effectively reducing the overall size of the injector and facilitating its arrangement in a limited space.

[0017] 5. In this invention, both the duty nozzle and the main combustion nozzle adopt a gas swirling nozzle structure. After passing through the swirler, the gas forms a high-speed swirling field in the swirling cup. After the fuel is ejected from the fuel nozzle on the wall, it is rapidly broken and atomized under strong shearing and fully mixed with the gas. The reflux zone formed after the swirling jet is ejected can entrain the already burned high-temperature products to the vicinity of the nozzle outlet, thereby continuously igniting the fresh mixture and realizing the self-sustaining stable combustion of the flame. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a cross-sectional view of the overall structure in this invention; Figure 2 This is a schematic diagram of the gas guiding mechanism in this invention; Figure 3 This is a cross-sectional view of the duty nozzle in this invention; Figure 4 This is a schematic diagram of a flame tube with a lobed cross-section in this invention; Figure 5 This is a schematic diagram of a flame tube with a circular cross-section in this invention.

[0019] In the diagram: 1. Injector panel; 2. Injector housing; 3. Gas guiding mechanism; 301. Flow guide; 302. High-pressure air flow channel; 303. Flame tube; 304. Cooling hole; 305. Ignition rod; 306. High-temperature oxygen-enriched gas flow channel; 4. Duty nozzle; 401. Swirl generator; 402. Swirl cup; 403. Fuel flow channel; 404. Fuel nozzle; 5. Main combustion nozzle; 6. Fuel supply pipeline. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0021] Example 1 In existing technologies, with the increase in combustion chamber size and power density, multi-nozzle injector structures are widely used. However, for large-scale injection disks, the energy provided by the local igniter is insufficient to ignite all nozzles simultaneously, easily leading to localized flameout. Traditional staged ignition schemes rely heavily on complex ignition control timing, placing extremely high demands on the reliability of the igniter and control system. Furthermore, for wide-condition engines with significant variations in gas velocity depending on operating flow rate, it is difficult to guarantee stable combustion throughout the entire operating envelope. To address this technical deficiency in existing technologies, such as... Figure 1 , Figure 2 As shown, this embodiment proposes an ejector-type multi-nozzle swirl injector, which can use the high-temperature oxygen-enriched standby flame generated by the standby nozzle 4 as a stable ignition source. At the same time, it relies on the standby flame to ignite each ring of main combustion nozzles 5 in sequence by propagating along the flame tube 303, thus achieving stable and reliable ignition and combustion in the entire operating range. The injector includes an injector panel 1, and an injector housing 2 is provided on the upstream side of the injector panel 1. The injector housing 2 is provided with a gas guiding mechanism 3 inside to separate the airflow entering the injector housing 2 into an oxygen-enriched gas flow path and an air flow path.

[0022] Specifically, the gas guiding mechanism 3 includes a guide shroud 301 disposed inside the injector housing 2. The guide shroud 301 is a streamlined through-structure with a cross-section that gradually narrows along the airflow direction. The inner wall of the guide shroud 301 encloses and forms a high-temperature oxygen-rich gas flow channel 306. Multiple main combustion nozzles 5 are arranged circumferentially around the duty nozzle 4 on the injector panel 1. A high-pressure air flow channel 302 is formed between the outer wall of the guide shroud 301 and the inner wall of the injector housing 2. The inlet of the main combustion nozzle 5 is connected to the high-pressure air flow channel 302. The fuel inlets of the duty nozzle 4 and the main combustion nozzle 5 are connected to a fuel supply pipeline 6. The gas guiding mechanism 3 physically isolates the high-temperature oxygen-rich gas from the high-pressure air at the gas source, allowing the duty nozzle 4 to operate at a high temperature. A warm, oxygen-rich environment is used to achieve a wide range of stable flame characteristics. Simultaneously, the main combustion nozzle 5 operates in a high-pressure air environment to ensure normal combustion organization in the main combustion zone. These two processes do not interfere with each other. The flow guide shroud 301 adopts a streamlined, tapering design. On one hand, it accelerates and guides the high-temperature, oxygen-rich gas flow, reducing flow losses. On the other hand, its outer wall surface naturally forms an annular high-pressure air flow channel 302 with the inner wall surface of the injector housing 2, eliminating the need for additional partition components and reducing the overall size of the injector. A duty nozzle 4, connected to the high-temperature, oxygen-rich gas flow channel 306, is located inside the bottom of the injector housing 2. A flame tube 303 is positioned between the outlet end face of the duty nozzle 4 and the injector panel 1. The outlet end face of the flame tube 303 is coplanar with the injector panel 1. The cross-sectional shape of the flame tube 303 can be either circular or corrugated. The axial expansion angle of the flame tube 303 ranges from 0° to 10°, and the length of the flame tube 303 along the axial direction is no more than 200 mm. The cross-sectional shape of the flame tube 303 affects the mixing efficiency between the standby flame and the surrounding airflow. A circular cross-section is simple to process and has good flow symmetry, while a corrugated cross-section can form an alternating concave-convex profile around the flame tube 303, increasing the contact area and mixing channel between the internal and external airflows of the flame tube 303. This is beneficial for the mixing of the standby high-temperature combustion gas and the surrounding air, accelerating the staged ignition process. Multiple cooling holes 304 are provided on the wall of the flame tube 303 for drawing in air under the action of the standby flame to form a cooling film. Multiple rows of cooling holes 304 are evenly distributed along the circumference of the side wall of the flame tube 303. The shape of the cooling holes 304 is at least one of circular holes, raindrop-shaped holes, or elliptical holes. The equivalent aperture of the cooling holes 304 is not less than 2 mm to ensure sufficient cooling air flow under limited pressure difference drive. When raindrop-shaped holes are used, their cross-sectional configuration of pointed top and round bottom has the process feature of top self-forming, which is especially suitable for laser selective melting forming process. It can effectively avoid the quality defect of top arc collapse during the forming process of large-diameter circular holes. Ignition mounting holes are opened on the wall surface of the flame tube 303. An ignition rod 305 for igniting the mixture sprayed by the duty nozzle 4 is inserted into the ignition mounting hole. The axis of the ignition rod 305 is arranged at a certain angle with the axis of the injector.This ensures that the electric spark generated by the ignition rod 305 covers the mixing area of ​​fuel and high-temperature oxygen-rich gas within the flame tube 303, thereby guaranteeing a high ignition success rate.

[0023] As can be seen from the above, during the ignition operation, the high-temperature oxygen-enriched gas enters the duty nozzle 4 through the high-temperature oxygen-enriched gas flow channel 306 inside the guide shroud 301. At the same time, the fuel is supplied to the fuel inlet of the duty nozzle 4 through the fuel supply pipeline 6. The two are mixed inside the duty nozzle 4 and then sprayed into the flame tube 303.

[0024] Due to the constraint of the flame tube 303 wall, the swirling mixture of high-temperature oxygen-enriched gas and fuel will form a reflux zone inside the flame tube 303, thereby enabling the fuel and high-temperature oxygen-enriched gas to mix fully and remain for a sufficiently long reaction time.

[0025] Then, the ignition rod 305 is energized to generate an electric spark, which ignites the mixture in the flame tube 303 to form a stable standby flame. At this time, the high temperature and oxygen-rich environment will significantly increase the flame propagation speed. Under the condition of wide variation in flow velocity, it can still match the incoming flow velocity. Therefore, the standby flame is not easily blown out and has a wide stable flame range.

[0026] After the standby flame is formed, the high-temperature and high-speed standby flame jet will create a negative pressure zone inside the flame tube 303, forming a pressure difference with the high-pressure air flow channel 302 outside the flame tube 303. Driven by this pressure difference, part of the air in the high-pressure air flow channel 302 will be drawn into the flame tube 303 through the cooling holes 304 on the wall of the flame tube 303, and flow along the inner wall of the flame tube 303 to form a cooling air film, thereby providing thermal protection for the wall of the flame tube 303. Moreover, the air flow rate drawn in accounts for no more than 0.5% of the total air flow rate, so it will not have a significant impact on the equivalence ratio of the standby flame area.

[0027] After the duty flame is ejected from the outlet end face of the flame tube 303, it first ignites the fuel and high-pressure air mixture ejected from the main combustion nozzle 5 closest to the duty nozzle 4. Subsequently, the ignited main combustion nozzle 5 will form a new high-temperature combustion zone, which will expand radially outward, thereby igniting the next ring of main combustion nozzles 5 in turn. This process continues until all the main combustion nozzles 5 are ignited, completing the ignition process of the entire combustion chamber.

[0028] Furthermore, the outlet end face of the flame tube 303 is coplanar with the injector panel 1, which ensures that the flame can propagate directly outward along the panel surface after being ejected, thus shortening the ignition path and improving the reliability of ignition.

[0029] Example 2 To further improve the mixing efficiency of fuel and gas and broaden the stable combustion operating range of each nozzle, based on Example 1, this example sets both the standby nozzle 4 and the main combustion nozzle 5 as gas swirl nozzles. The gas swirl nozzle includes a swirler 401, a swirl cup 402, a fuel channel 403, and a fuel nozzle 404 arranged sequentially along the airflow direction. The fuel channel 403 is connected to the fuel supply pipeline 6, and the fuel nozzle 404 is opened on the wall of the swirl cup 402. After the gas passes through the swirler 401, it will generate rotational momentum and form a high-speed swirling field in the swirl cup 402. After the fuel is ejected from the fuel nozzle 404 on the wall of the swirl cup 402, it will be rapidly broken up and atomized under strong shearing and fully mixed with the swirling gas. After the swirling jet is ejected, it will form a backflow zone in the flame tube 303 or combustion chamber, which plays a role in stabilizing the flame. This can effectively broaden the stable combustion operating range for both the standby nozzle 4 and the main combustion nozzle 5.

[0030] As can be seen from the above, after the high-temperature oxygen-enriched gas enters the cyclone separator 401, it will generate rotational momentum, thereby forming a high-speed swirling field in the cyclone cup 402. Furthermore, the fuel will be transported to the fuel flow channel 403 through the fuel supply pipeline 6, and then ejected from the fuel injection hole 404 on the wall of the cyclone cup 402.

[0031] At this point, the fuel jet is rapidly broken into fine droplets and atomized under the strong shearing action of the high-speed swirling gas, thus achieving full mixing with the high-temperature oxygen-rich gas to form a uniform combustible mixture.

[0032] Moreover, the expansion structure set at the outlet section of the swirl cup 402 will cause the swirl jet to expand further after it is ejected, forming a large-scale recirculation zone inside the flame tube 303. This recirculation zone can entrain the already burned high-temperature products to the vicinity of the nozzle outlet, continuously ignite the fresh mixture, and achieve self-sustaining stable combustion of the standby flame.

[0033] For the main combustion nozzle 5, the high-pressure air will also generate a swirling flow after passing through the swirler 401. After the fuel is injected from the fuel injection hole 404, it will mix with the swirling air and then be injected into the combustion chamber to form stable combustion. Since the swirling jet itself has the characteristic of backflow and flame stabilization, the main combustion nozzle 5 can maintain stable combustion in a wide range of operating conditions and is not easy to extinguish after being ignited by the duty flame.

[0034] The duty nozzle 4 and the main combustion nozzle 5 adopt the same swirling nozzle configuration, which is conducive to the standardized design and manufacturing of the injector as a whole, reduces processing costs and maintenance difficulties. Moreover, the multiple main combustion nozzles 5 work independently, so even if the combustion of individual nozzles is unstable, it will not affect the normal operation of other nozzles, thus improving the combustion stability and fault tolerance of the entire combustion chamber.

[0035] Example 3 This embodiment provides an ignition method using the above-mentioned ejector-type multi-nozzle swirl injector, including the following steps: S1: High-temperature oxygen-enriched gas is introduced into the duty nozzle 4 through the high-temperature oxygen-enriched gas flow channel 306 via the gas guiding mechanism 3, and high-pressure air is introduced into each main combustion nozzle 5 through the high-pressure air flow channel 302. At the same time, fuel is supplied to the duty nozzle 4 and the main combustion nozzle 5 through the fuel supply pipeline 6, so that the fuel is mixed with the high-temperature oxygen-enriched gas in the duty nozzle 4 and mixed with the high-pressure air in the main combustion nozzle 5 respectively. S2: Under the constraint of the wall of the flame tube 303, the high-temperature oxygen-rich gas ejected by the duty nozzle 4 and the swirling mixture of fuel form a reflux zone inside the flame tube 303, which makes the fuel and the high-temperature oxygen-rich gas fully mixed and prolongs the residence time of the mixture, preparing for ignition. S3: When the ignition rod 305 is energized, it generates an electric spark, which ignites the high-temperature oxygen-rich gas and fuel mixture inside the flame tube 303. Due to the fast chemical reaction rate and high flame propagation speed in the high-temperature oxygen-rich environment, it can still match the incoming flow velocity even under conditions of wide variation in flow velocity. Therefore, it is easy to ignite and has a wide flame stabilization range, forming a stable standby flame. S4: After the standby flame is formed, the high-temperature and high-speed standby flame jet creates a negative pressure zone inside the flame tube 303, generating an ejection effect. This causes some of the air in the high-pressure air channel 302 to be drawn into the flame tube 303 through the cooling holes 304 on the wall of the flame tube 303 under the pressure difference. The air then flows along the inner wall of the flame tube 303 to form a cooling gas film, which cools and protects the wall of the flame tube 303. The air flow through the cooling holes 304 accounts for no more than 0.5% of the total air flow, ensuring that the equivalence ratio impact on the standby flame area is minimized. S5: The duty flame spreads downstream along the flame tube 303 and is ejected from the outlet end face of the flame tube 303. It first ignites the mixture of fuel and high-pressure air ejected from the main combustion nozzles 5 closest to the duty nozzle 4. The ignited main combustion nozzles 5 form a new high-temperature combustion zone. S6: The new high-temperature combustion zone expands further outward along the radial direction, igniting the remaining main combustion nozzles 5 one by one until all the main combustion nozzles 5 are ignited, achieving stable ignition of the entire combustion chamber.

[0036] In this embodiment, steps S1 to S6 are executed sequentially, with step S4 being performed synchronously with steps S5 and S6. The ejector cooling effect of the standby flame continues to act after the standby flame is formed, running through the entire step-by-step ignition process. The ignition rod 305 is only energized in step S3 and can be de-energized and removed after the standby flame is formed. This method does not require complex ignition timing control and only requires a single ignition to complete the start-up of the entire multi-nozzle injector.

[0037] The control method of this invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the art. Furthermore, since this invention is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail here.

[0038] It should be noted that the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0039] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An ejector-type multi-nozzle swirl injector, comprising an injector panel (1), wherein an injector housing (2) is disposed on the upstream side of the injector panel (1), characterized in that: The inside of the injector housing (2) is provided with a gas guiding mechanism (3) for separating the airflow entering the injector housing (2) into an oxygen-rich gas flow path and an air flow path. The gas guiding mechanism (3) includes a guide shroud (301) disposed inside the injector housing (2), which divides the interior of the injector housing (2) into a high-temperature oxygen-rich gas flow channel (306) and a high-pressure air flow channel (302). The bottom of the injector housing (2) is provided with a duty nozzle (4) that communicates with the high temperature oxygen-rich gas flow channel (306). A flame tube (303) is provided between the outlet end face of the duty nozzle (4) and the injector panel (1). The outlet end face of the flame tube (303) is coplanar with the injector panel (1). Multiple cooling holes (304) are provided on the wall of the flame tube (303) for drawing in air to form a cooling gas film under the action of the duty flame. Multiple main combustion nozzles (5) are arranged around the duty nozzle (4) on the injector panel (1). The inlet of the main combustion nozzle (5) is connected to the high-pressure air flow channel (302). The fuel inlets of the duty nozzle (4) and the main combustion nozzle (5) are connected to the fuel supply pipeline (6).

2. The ejector-type multi-nozzle swirl injector according to claim 1, characterized in that: The flow guide (301) is a streamlined through structure with a cross section that gradually shrinks along the airflow direction. The inner wall of the flow guide (301) encloses and forms a high-temperature oxygen-rich gas flow channel (306). A high-pressure air flow channel (302) is formed between the outer wall of the flow guide (301) and the inner wall of the injector housing (2).

3. The ejector-type multi-nozzle swirl injector according to claim 1, characterized in that: The main combustion nozzle (5) has a multi-row structure and is arranged concentrically from the inside to the outside along the radial direction of the injector panel (1). Adjacent rows of main combustion nozzles (5) are alternately distributed in the circumferential direction.

4. The ejector-type multi-nozzle swirl injector according to claim 1, characterized in that: The duty nozzle (4) and the main combustion nozzle (5) are both gas swirling nozzles. The gas swirling nozzle includes a swirler (401), a swirling cup (402), a fuel flow channel (403), and a fuel injection hole (404) arranged sequentially along the airflow direction. The fuel flow channel (403) is connected to the fuel supply pipeline (6), and the fuel injection hole (404) is opened on the wall of the swirling cup (402).

5. The ejector-type multi-nozzle swirl injector according to claim 1, characterized in that: The cross-sectional shape of the flame tube (303) is either circular or wavy, the expansion angle of the flame tube (303) along the axial direction is 0° to 10°, and the length of the flame tube (303) along the axial direction is not greater than 200mm.

6. The ejector-type multi-nozzle swirl injector according to claim 1, characterized in that: The cooling holes (304) are evenly distributed in multiple rows along the circumference of the side wall of the flame tube (303), and the shape of the cooling holes (304) is at least one of circular holes, raindrop-shaped holes or elliptical holes.

7. The ejector-type multi-nozzle swirl injector according to claim 1, characterized in that: An ignition mounting hole is provided on the wall of the flame tube (303), and an ignition rod (305) for igniting the mixture sprayed by the duty nozzle (4) is inserted into the ignition mounting hole.

8. An ignition method for an ejector-type multi-nozzle swirl injector, employing the ejector-type multi-nozzle swirl injector as described in any one of claims 1 to 7, characterized in that, Includes the following steps:

1. High-temperature oxygen-enriched gas is introduced into the duty nozzle (4) through the gas guiding mechanism (3), and high-pressure air is introduced into each main combustion nozzle (5). At the same time, fuel is supplied to the duty nozzle (4) and the main combustion nozzle (5) so that the fuel is mixed with the high-temperature oxygen-enriched gas and high-pressure air under the action of swirling flow. Second, under the constraint of the flame tube (303) wall, the mixture of high-temperature oxygen-rich gas and fuel ejected by the duty nozzle (4) forms a reflux zone inside the flame tube (303), which promotes the full mixing of fuel and high-temperature oxygen-rich gas.

3. The mixture inside the flame tube (303) is ignited by the ignition rod (305) to form a stable standby flame in a high-temperature and oxygen-rich environment; Fourth, the high-speed jet of the flame creates a negative pressure zone inside the flame tube (303), generating an ejection effect. Part of the air in the high-pressure air channel (302) is drawn into the flame tube (303) through the cooling holes (304) on the wall of the flame tube (303), and flows along the inner wall of the flame tube (303) to form a cooling gas film, which cools the wall of the flame tube (303). Fifth, the duty flame spreads downstream along the flame tube (303), igniting the mixture of fuel and high-pressure air ejected from the main combustion nozzle (5) closest to the duty nozzle (4), and the ignited main combustion nozzle (5) forms a new high-temperature combustion zone; VI. The new high-temperature combustion zone expands radially outward, igniting the remaining main combustion nozzles (5) one by one until all the main combustion nozzles (5) are ignited, completing the ignition of the entire combustion chamber.

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