A premixed fuel injector and engine

Abstract

The application belongs to the technical field of fuel injection and provides a premixed fuel injector and an engine. The injector comprises an inner fuel pipe and an outer fuel pipe coaxially sleeved, the axis direction of the inner fuel pipe is a first direction, the inner fuel pipe comprises a first pipe section and a second pipe section distributed along the first direction, the inner passage of the first pipe section is a first fuel flow field, and the gap passage between the first pipe section and the outer fuel pipe is a second fuel flow field; the second pipe section comprises at least one pipe section with gradually increasing inner diameter and at least one pipe section with gradually decreasing inner diameter, and the second pipe section has a plurality of counterflow holes, part of the counterflow holes are located on the feeding path of the first fuel flow field, and part of the counterflow holes are located on the feeding path of the second fuel flow field. The application limits the inner diameter of the second pipe section, sets the counterflow holes on the feeding path of the first fuel flow field and the feeding path of the second fuel flow field, and mixes the fuels in the first fuel flow field and the second fuel flow field.

Description

Technical Field

[0001] This invention belongs to the field of fuel injection technology, specifically relating to a premixed fuel injector and an engine. Background Technology

[0002] Fuel injection is located in the combustion chamber of a scramjet engine, where fuel can be injected from the walls, baffles, or injector rods. The supersonic flow within the engine creates significant drag on intrusive structures; therefore, currently used fuel injector structures are non-intrusive.

[0003] In related technologies, the dual-fuel injection method for scramjet engines employs a multi-injector injection method, where each injector contains one type of fuel and multiple injectors are connected in parallel. The two fuels are not pre-mixed, making ignition more difficult, and combustion stability and efficiency need to be improved. Summary of the Invention

[0004] The purpose of this invention is to provide a premixed fuel injector and engine to solve the aforementioned technical problems in the background art.

[0005] This invention is implemented as follows:

[0006] In a first aspect, this application provides a premixed fuel injector, including an inner fuel tube and an outer fuel tube coaxially sleeved together. The axial direction of the inner fuel tube is a first direction. The inner fuel tube includes a first tube segment and a second tube segment distributed along the first direction. The inner channel of the first tube segment is a first fuel flow domain, and the gap channel between the first tube segment and the outer fuel tube is a second fuel flow domain. The second tube segment includes at least one tube segment with a gradually increasing inner diameter and at least one tube segment with a gradually decreasing inner diameter. The second tube segment has multiple convection holes, some of which are located on the feeding path of the first fuel flow domain and some of which are located on the feeding path of the second fuel flow domain.

[0007] Secondly, this application also provides an engine, including a premixed fuel injector provided in the first aspect.

[0008] The beneficial effects of this invention are:

[0009] In this invention, by coaxially sleeved inner and outer fuel pipes, two types of fuel can be introduced simultaneously. By limiting the inner diameter of the second pipe section and providing convection holes on it, some of these holes are located on the feeding path of the first fuel flow region, allowing fuel in the first fuel flow region to pass through and enter the outer fuel pipe for mixing. Similarly, some convection holes are located on the feeding path of the second fuel flow region, allowing fuel in the second fuel flow region to pass through and enter the inner fuel pipe for mixing. This double mixing of fuel in the first and second fuel flow regions enhances the mixing degree of the two fuels, thereby reducing the difficulty of fuel ignition and increasing combustion stability and efficiency. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments of the present invention or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the overall structure of the injector provided in some embodiments of this application;

[0012] Figure 2 This is a cross-sectional view of the injector provided in some embodiments of this application. Figure 1 ;

[0013] Figure 3 This is a cross-sectional view of the injector provided in some embodiments of this application. Figure 2 ;

[0014] Figure 4 This is a schematic diagram of the structure of the inner fuel pipe provided in some embodiments of this application;

[0015] Figure 5 This is a schematic diagram of the structure of the outer fuel pipe provided in some embodiments of this application;

[0016] Figure 6 This is a cross-sectional view of the outer fuel pipe provided in some embodiments of this application;

[0017] In the picture:

[0018] 100 - Inner fuel pipe, 110 - First pipe section, 111 - Turbulence hole, 120 - Second pipe section, 121 - Convection hole, 200 - Outer fuel pipe, 210 - Third pipe section, 220 - Fourth pipe section, 230 - Discharge port, 300 - First fuel flow area, 400 - Second fuel flow area, 500 - Guide plate. Detailed Implementation

[0019] The following description provides many different embodiments or examples for implementing various features of the invention. The elements and arrangements described in the specific examples below are only for concise expression of the invention and are merely examples, not intended to limit the invention.

[0020] This application provides a premixed fuel injector, referencing... Figures 1 to 6 As shown, the injector includes an inner fuel pipe 100 and an outer fuel pipe 200 coaxially sleeved together, with the outer fuel pipe 200 sleeved outside the inner fuel pipe 100. The axial direction of either the inner fuel pipe 100 or the outer fuel pipe 200 is defined as a first direction. The inner fuel pipe 100 includes a first pipe section 110 and a second pipe section 120 distributed along the first direction. The internal channel of the first pipe section 110 is designated as a first fuel flow area 300 for introducing one type of fuel. The gap between the first pipe section 110 and the outer fuel pipe 200 is designated as a second fuel flow area 400 for introducing another type of fuel. This arrangement allows two types of fuel to be introduced into the injector simultaneously, reducing the number of injectors required in the combustion chamber. (First direction reference) Figure 1 The direction of the dashed arrow shown.

[0021] The second section 120 of the inner fuel pipe 100 includes at least one section with a gradually increasing inner diameter and at least one section with a gradually decreasing inner diameter, so that the pipe wall of the second section 120 has an undulating shape. Part of the pipe wall of the second section 120 is located on the feeding path of the first fuel flow domain 300, and part of the pipe wall is located on the feeding path of the second fuel flow domain 400. Multiple convection holes 121 are provided on the second section 120. With this arrangement, some of the convection holes 121 are located on the feeding path of the first fuel flow domain 300, and some of the convection holes 121 are located on the feeding path of the second fuel flow domain 400.

[0022] It should be noted that when fuel is fed into the first fuel flow domain 300 and the second fuel flow domain 400, the fuel is constrained by the inner wall of the fuel flow domain, which restricts the flow of the fuel within a certain range. After the fuel exits the fuel flow domain, it can continue to move forward due to inertia. The range in which the fuel continues to move forward is the fuel feeding path.

[0023] After fuel flows out of the first fuel flow domain 300, some fuel flows through the convection holes 121 located on the feed path of the first fuel flow domain 300, reaching the outer side of the inner fuel pipe 100 and the inner side of the outer fuel pipe 200, where it mixes with the fuel flowing out of the second fuel flow domain 400. Similarly, after fuel flows out of the second fuel flow domain 400, some fuel flows through the convection holes 121 located on the feed path of the second fuel flow domain 400, reaching the inner fuel pipe 100, where it mixes with the fuel flowing out of the first fuel flow domain 300. The fuel entering from the first fuel flow domain 300 and the second fuel flow domain 400 undergoes two mixing processes, increasing the miscibility of the two fuels. This makes the mixed fuel easier to ignite and improves combustion stability. The pre-mixed fuel molecules are more evenly distributed, reducing the possibility of a time gap between the peak combustion temperatures of the two fuels, which is beneficial for stable combustion in the scramjet engine.

[0024] In specific implementation, the port of the first section 110 of the inner fuel pipe 100 serves as the inner feed inlet, and the first fuel flow domain 300 is connected to the inner feed inlet. The port of the outer fuel pipe 200 near the inner feed inlet serves as the outer feed inlet, and the second fuel flow domain 400 is connected to the outer feed inlet. The first fuel flow domain 300 is generally supplied with fuels with low laminar flame velocities, i.e., non-flammable fuels, such as liquid ammonia. The second fuel flow domain 400 is generally supplied with fuels with high laminar flame velocities, i.e., flammable fuels, such as liquid methane or hydrogen. The two fuels flow in the same direction, making fuel control easier. The port of the second section 120 of the inner fuel pipe 100 serves as the inner discharge outlet 230, and the port of the outer fuel pipe 200 near the inner discharge outlet 230 serves as the outer discharge outlet 230. The premixed fuel flows out from both the inner and outer discharge outlets 230. Non-flammable fuel is introduced through the inner fuel pipe 100, and flammable fuel is introduced through the outer fuel pipe 200. The ignition device ignites the non-flammable fuel with the flammable fuel, thus expanding the flammability limit of the fuel.

[0025] In some embodiments of this application, the second pipe section 120 may have multiple pipe sections with gradually decreasing inner diameters and multiple pipe sections with gradually increasing inner diameters. With this arrangement, the non-flammable fuel inside the inner fuel pipe 100 and the flammable fuel outside the inner fuel pipe 100 are mixed multiple times, thereby increasing the degree of fuel blending. For example, the inner diameter of the second pipe section 120 first gradually decreases, so that the convection orifice 121 is located on the feeding path of the first fuel flow domain 300; then the inner diameter of the second pipe section 120 gradually increases, so that the convection orifice 121 is located on the feeding path of the second fuel flow domain 400. Then the inner diameter of the second pipe section 120 decreases and then increases again, repeating this process, allowing the flammable and non-flammable fuels to mix multiple times, improving the degree of premixing. The number of changes in the inner diameter of the second pipe section 120 can be set according to the actual required fuel blending ratio.

[0026] In some other preferred embodiments of this application, the second pipe segment 120 along the direction from the first pipe segment 110 to the second pipe segment 120 includes a first sub-pipe segment with a gradually increasing inner diameter and a second sub-pipe segment with a gradually decreasing inner diameter. The inner diameter of the second pipe segment 120 gradually increases and then gradually decreases, and the port of the second pipe segment 120 with the decreasing inner diameter serves as the inner layer outlet 230. The second pipe segment 120 with the increased inner diameter is raised, and the convection hole 121 located at this part is on the feeding path of the second fuel flow domain 400, as shown in the reference. Figure 3 As shown, after the flammable fuel flows out of the second fuel flow area 400, it enters the inner fuel pipe 100 through the convection hole 121, mixing with the non-flammable fuel in the inner fuel pipe 100 to complete the initial premixing. The inner wall of the second pipe section 120, with its decreasing inner diameter, gradually moves towards its axis. The convection hole 121 located at this position is on the feeding path of the first fuel flow area 300. After the non-flammable fuel flows out of the first fuel flow area 300, it enters the outer side of the inner fuel pipe 100 and the inner side of the outer fuel pipe 200 through the convection hole 121, mixing with the flammable fuel. Furthermore, the flammable fuel, after initially mixing with the non-flammable fuel through the convection hole 121, can pass through the preceding convection hole 121 and re-enter the feeding path of the second fuel flow area 400 during its continued forward transport, mixing with the flammable fuel in this area to further deepen the mixing.

[0027] In this layout, since the inner diameter of the second pipe section 120 increases first, after the non-flammable fuel flows from the first pipe section 110 into the second pipe section 120, the increased inner diameter of the second pipe section 120 causes diffusion at the edges of the non-flammable fuel. This allows the non-flammable fuel to pass through other convection holes 121 and enter the feeding path of the second fuel flow domain 400, where it mixes with the flammable fuel. Other convection holes 121 refer to those that are not located, or whose majority of their internal space is not located, within the feeding paths of the first fuel flow domain 300 and the second fuel flow domain 400. By fully utilizing the convection holes 121 on the second pipe section 120, obstruction in the fuel flow path is reduced, thereby reducing fuel flow resistance.

[0028] The inner diameter of the second pipe section 120 gradually increases and then gradually decreases. Since some of the convection holes 121 need to be located on the feeding path of the first fuel flow region 300, the inner diameter of the port of the second pipe section 120 after the inner diameter decreases must be smaller than the inner diameter of the first pipe section 110. However, considering the flow resistance of the fuel, the inner diameter of the port of the second pipe section 120 cannot be too small; it is generally about half the inner diameter of the first pipe section 110.

[0029] To cooperate with the inner fuel pipe 100, the outer fuel pipe 200 also includes a third pipe section 210 and a fourth pipe section 220 distributed along the first direction. The fourth pipe section 220 is fitted outside the second pipe section 120, and the third pipe section 210 is fitted outside the first pipe section 110. During the premixing process of flammable and non-flammable fuels, a portion of the space within the second pipe section 120 and the gap between the second pipe section 120 and the fourth pipe section 220 serve as flow channels during the premixing process.

[0030] In some embodiments of this application, as the inner diameter of the second pipe section 120 gradually increases and then decreases along the fuel feed direction, to enhance the flowability of the fuel during the premixing process, the inner diameter of the fourth pipe section 220 is configured to change in the opposite direction to that of the second pipe section 120. This causes the fuel flow cross-section to first narrow and then widen. The fuel velocity increases as it passes through the narrower flow channel, and then it enters the wider flow channel, where it diffuses, improving the premixing degree and enhancing the mixing effect. Furthermore, this arrangement allows for a certain degree of equilibrium between the flow velocities of non-flammable and flammable fuels during the flow through the flow channel with its changing cross-sectional dimensions, thus balancing the flow velocities of the two fuels.

[0031] In some other embodiments of this application, along the fuel feed direction, when the inner diameter of the second pipe section 120 gradually increases and then decreases, the inner diameter of the fourth pipe section 220 follows the same trend as that of the second pipe section 120. The inner diameter of the fourth pipe section 220 also gradually increases and then gradually decreases. The fourth pipe section 220 includes a third sub-pipe section with a gradually increasing inner diameter and a fourth sub-pipe section with a gradually decreasing inner diameter. This arrangement ensures that the cross-section of the gap channel between the fourth pipe section 220 and the second pipe section 120 remains as consistent as possible, providing sufficient premixing space for the two fuels. Furthermore, since the area of ​​the flow cross-section does not change significantly, the overall fuel flow velocity does not differ greatly from the initial velocity entering the injector, which helps control the speed at which the fuel enters the combustion chamber and improves fuel control.

[0032] Furthermore, in this layout, because the inner diameter of the discharge end of the fourth pipe section 220 gradually decreases, the fuel ejected from the fourth pipe section 220 tends to converge towards its axis. Also, the fourth pipe section 220 is coaxially arranged with the second pipe section 120, and the fuel ejected from the second pipe section 120 is ejected along its axis. The paths of the fuel ejected from the fourth pipe section 220 and the fuel ejected from the second pipe section 120 overlap. (Reference) Figure 3 As shown, the dashed arrows extending from the pipe wall of the fourth pipe section 220 represent the flow trend of the fuel ejected from the fourth pipe section 220, which tends to converge towards the center; the dashed arrows extending from the pipe wall of the second pipe section 120 represent the flow trend of the fuel ejected from the second pipe section 120. The fuel paths of the two flow trends overlap and mix with each other during the flow process, further enhancing the mixing between flammable and non-flammable fuels.

[0033] During the flow process, some of the non-flammable fuel located in the inner fuel pipe 100 near the inner wall of the inner fuel pipe 100 can pass through the convection holes 121 and mix with the flammable fuel, or some of the fuel near the inner wall of the inner fuel pipe 100 can mix with the flammable fuel passing through the convection holes 121. The fuel located around the axis of the inner fuel pipe 100 is less disturbed and can continue to flow in its original direction until it exits the second pipe section 120, and then mixes with the fuel in the fourth pipe section 220, thereby mixing all or most of the fuel in the inner fuel pipe 100.

[0034] In some preferred embodiments of this application, the inner diameter change rate of the second pipe segment 120 is similar to that of an ellipsoidal or spherical structure, and the inner diameter change rate of the fourth pipe segment 220 is also similar to that of an ellipsoidal or spherical structure. This results in a smooth change in the inner wall of the pipe segments, reducing the flow resistance that may be caused to the fuel during the fuel flow process. For example, cutting off the radial ends of an ellipsoidal structure can form either a fourth pipe segment 220 or a second pipe segment 120 with a gradually increasing and then gradually decreasing inner diameter. The second pipe segment 120 and the fourth pipe segment 220 can be considered as parts of a spherical or ellipsoidal structure. (Refer to...) Figure 4 and Figure 5 As shown.

[0035] In some preferred embodiments, the fourth pipe segment 220 is located away from the outlet inner diameter of the third pipe segment 210, i.e., the discharge port of the fourth pipe segment 220. The inner diameter of this discharge port is larger than the outer diameter of the second pipe segment 120. Furthermore, the end of the second pipe segment 120 away from the first pipe segment 110 is located within the fourth pipe segment 220, and the entire second pipe segment 120 is located within the fourth pipe segment 220. It should be noted that the outer diameter of the second pipe segment 120 refers to the outer diameter of all parts of the second pipe segment 120. The outlet inner diameter of the fourth pipe segment 220 is larger than the outer diameter of the second pipe segment 120, meaning that even the maximum outer diameter of the second pipe segment 120 is smaller than the outlet inner diameter of the fourth pipe segment 220.

[0036] If the outlet inner diameter of the fourth pipe section 220 is too small, some fuel will collide with the pipe wall during its exit from the fourth pipe section 220, increasing the flow resistance of the fuel and hindering fuel injection. Furthermore, by increasing the outlet inner diameter of the fourth pipe section 220, the injection angle of the fuel ejected from the fourth pipe section 220 can be reduced, thereby lengthening its intersection path with the fuel ejected from the second pipe section 120 and improving the mixing degree of the two fuels. Since the outlet inner diameter of the fourth pipe section 220 is larger than the outer diameter of the second pipe section 120, the fuel passing through the convection orifice 121 of the second pipe section 120 hardly contacts the pipe wall of the fourth pipe section 220 during its exit, effectively reducing the flow velocity of this portion of fuel. Meanwhile, the fuel ejected from the second fuel flow area 400 that does not pass through the convection orifice 121 has a higher velocity than the fuel that does. A portion of this fuel contacts the pipe wall of the fourth pipe section 220, reducing its flow velocity, thus balancing the fuel flow velocity.

[0037] In a further preferred embodiment, the outlet inner diameter of the fourth pipe section 220 is smaller than the inlet inner diameter of the fourth pipe section 220. With this structure, the constraint effect of the fourth pipe section 220 on the fuel is improved, so that the fuel injected from the fourth pipe section 220 can smoothly gather towards the center and mix with the fuel injected from the second pipe section 120.

[0038] In some embodiments of this application, the outer diameter of the second pipe section 120 is set to be smaller than the inner diameter of the third pipe section 210. A portion of the fuel ejected from the third pipe section 210 can enter the second pipe section 120 without passing through the convection hole 121. This portion of fuel can mix with the fuel that passes through the convection hole 121 from the second pipe, reducing the flow resistance of the fuel ejected from the third pipe section 210 and making the fuel flow speed as stable as possible.

[0039] The injector is also equipped with a guide plate 500, which is used to increase the circumferential flow velocity of the fuel, thereby improving the fuel mixing degree. Specifically, multiple guide plates 500 are fixed on the inner wall of the third pipe section 210 or the outer wall of the first pipe section 110. The guide plates 500 are spirally arranged around the axis of the third pipe section 210, and there are multiple guide plates 500, which are rotationally symmetrical about the axis of the third pipe section 210.

[0040] The structure of the baffle 500 increases the circumferential velocity of the flammable fuel located in the second fuel flow domain 400. When the baffle 500 is installed on the inner wall of the third pipe section 210, refer to... Figure 2 , Figure 3 , Figure 5 and Figure 6 As shown, the flammable fuel, under the action of the guide plate 500, has a certain circumferential velocity on its outer layer. This helps to improve the mixing degree of the fuel during the mixing process between the fuel and the fuel exiting the second nozzle section 120. When the guide plate 500 is installed on the outer wall of the first nozzle, the inner layer of the flammable fuel has a certain circumferential velocity. When it enters the second nozzle section 120 and mixes with the non-flammable fuel, it can enhance the mixing degree of the two fuels.

[0041] The guide plate 500 can be disposed at the ends of the third pipe section 210 and the first pipe section 110 near the inlet, or in the middle, or near the end of the outlet 230, or extend directly from the inlet to the outlet 230 of the pipe section. In some embodiments of this application, the end face of the third pipe section 210 connected to the fourth pipe section 220, the end face of the first pipe section 110 connected to the second pipe section 120, and the end face of the guide plate 500 near the fourth pipe section 220 are disposed on the same plane, as shown in the reference. Figure 3 As shown, the fuel begins to mix with non-flammable fuel after its circumferential velocity changes, making full use of the fuel's circumferential velocity.

[0042] The outer fuel pipe 200 also includes a discharge port 230, which is connected to the fourth pipe section 220. The inner wall of the discharge port 230 is curved, and the inner diameter of the discharge port 230 first decreases and then increases along the direction from the fourth pipe section 220 to the discharge port 230. The curved structure helps to reduce the flow resistance of the fuel. Without affecting the convergence of the fuel towards the axis of the fourth pipe section 220, the gradual increase in the inner diameter of the discharge port 230 can increase the injection angle of the fuel ejected from the fourth pipe section 220, extend the mixing area of ​​the two fuels, and improve the mixing degree.

[0043] In some embodiments of this application, the plurality of convection holes 121 disposed on the second pipe section 120 are divided into multiple groups of convection hole groups. Each group of convection holes includes a plurality of convection holes 121 uniformly distributed circumferentially along the second pipe section 120, and the multiple groups of convection hole groups are uniformly distributed along a first direction. This balances the distribution density of the convection holes 121 on the second pipe section 120, reducing the impact of uneven distribution of the convection holes 121 on fuel flow resistance, thereby making the mixing of the two fuels more uniform.

[0044] In some preferred embodiments, the circumferential sidewall of the first pipe section 110 is provided with a plurality of turbulence holes 111. These turbulence holes 111 connect the inner and outer sides of the first pipe section 110 and are uniformly distributed circumferentially along the first pipe section 110. The turbulence holes 111 can alter the fluid boundary layer state on both sides of the first pipe section 110, initially increasing the fuel mixing degree on both sides of the first pipe section 110. The turbulence holes 111 are generally triangular in structure, with one apex facing the direction of fuel flow, in order to minimize the size of the turbulence holes 111 while maintaining the fuel mixing degree, thus preserving the structural strength of the first pipe section 110.

[0045] This application also provides an engine that includes the injector provided in any of the above embodiments. The engine can be a scramjet engine or other types of engines.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A premixed fuel injector characterized by, The premixed fuel injector comprises a coaxial inner fuel pipe (100) and an outer fuel pipe (200), the axis of the inner fuel pipe (100) is the first direction, the inner fuel pipe (100) comprises a first pipe section (110) and a second pipe section (120) arranged along the first direction, the inner passage of the first pipe section (110) is the first fuel flow field (300), and the gap passage between the first pipe section (110) and the outer fuel pipe (200) is the second fuel flow field (400); The second pipe section (120) comprises at least one pipe section with gradually increasing inner diameter and at least one pipe section with gradually decreasing inner diameter, and the second pipe section (120) has a plurality of convection holes (121), part of the convection holes (121) are located on the feeding path of the first fuel flow field (300), and part of the convection holes (121) are located on the feeding path of the second fuel flow field (400).

2. The premixed fuel injector according to claim 1, wherein Along the direction from the first pipe section (110) to the second pipe section (120), the second pipe section (120) comprises a first sub-pipe section with gradually increasing inner diameter and a second sub-pipe section with gradually decreasing inner diameter.

3. The premixed fuel injector according to claim 2, wherein The outer fuel pipe (200) comprises a third pipe section (210) and a fourth pipe section (220) arranged along the first direction, the fourth pipe section (220) is sleeved outside the second pipe section (120), and along the direction from the third pipe section (210) to the fourth pipe section (220), the fourth pipe section (220) comprises a third sub-pipe section with gradually increasing inner diameter and a fourth sub-pipe section with gradually decreasing inner diameter.

4. The premixed fuel injector according to claim 3, wherein The inner diameter of the fourth pipe section (220) away from the outlet of the third pipe section (210) is greater than the outer diameter of the second pipe section (120), and the end of the second pipe section (120) away from the first pipe section (110) is located in the fourth pipe section (220); And / or, the outer diameter of the second pipe section (120) is smaller than the inner diameter of the third pipe section (210).

5. The premixed fuel injector according to claim 3 or 4, wherein The inner side wall of the third pipe section (210) or the outer side wall of the first pipe section (110) is fixed with a plurality of guide plates (500), the guide plates (500) are spirally arranged around the axis of the third pipe section (210), and a plurality of the guide plates (500) are rotationally symmetrical around the axis of the third pipe section (210).

6. The premixed fuel injector according to claim 5, wherein The end face of the third pipe section (210) connected with the fourth pipe section (220), the end face of the first pipe section (110) connected with the second pipe section (120), and the end face of the guide plate (500) close to the fourth pipe section (220) are all in the same plane.

7. The premixed fuel injector according to claim 3 or 4, characterized in that, the outer fuel tube (200) further comprises a discharge port (230), the discharge port (230) is connected with the fourth tube section (220), and the inner side wall of the discharge port (230) is arc-shaped, and the inner diameter of the discharge port (230) first decreases and then increases along the direction from the fourth tube section (220) to the discharge port (230).

8. The premixed fuel injector according to claim 1, characterized in that, a plurality of the convection holes (121) are divided into a plurality of groups of convection holes, any group of convection holes comprises a plurality of convection holes (121) uniformly distributed along the circumference of the second tube section (120), and a plurality of groups of convection holes are uniformly distributed along the first direction; and / or, the circumferential side wall of the first tube section (110) is provided with a plurality of turbulence holes (111), and a plurality of the turbulence holes (111) are uniformly distributed along the circumference of the first tube section (110).

9. The premixed fuel injector according to claim 3 or 4, characterized in that, the second tube section (120) is part of an ellipsoidal structure or a spherical structure; and / or, the fourth tube section (220) is part of an ellipsoidal structure or a spherical structure.

10. An engine characterized by, The premixed fuel injector according to any one of claims 1-9.

Images