A needle injection injector and rocket engine

Abstract

The application provides a needle injector and a rocket engine, and relates to the technical field of space propulsion system engines.The application provides a needle injector, which comprises a needle body, a plurality of radial injection holes are circumferentially arranged on one end of the needle body, and the radial injection holes are used for radially injecting central working medium; a liquid collecting cavity shell is sleeved on the needle body, an annular gap injection port is formed between the needle body and the liquid collecting cavity shell, and the annular gap injection port is used for axially injecting outer ring working medium; an outwardly expanding flow guide structure is connected to one end of the needle body; wherein the axial projection of the annular gap injection port on one end of the needle body is located in the range of the outwardly expanding flow guide structure; the plurality of radial injection holes comprise a plurality of main holes and a plurality of auxiliary holes, the flow area of the main holes is greater than that of the auxiliary holes, the main holes are used for forming first jets capable of penetrating the outer ring working medium, and the auxiliary holes are used for forming second jets capable of penetrating into the outer ring working medium. The needle injector provided by the application can optimize the atomization effect and improve the overall combustion efficiency of the rocket engine.

Description

Technical Field

[0001] This application relates to the field of aerospace propulsion system engine technology, and in particular to a needle-plug injector and a rocket engine. Background Technology

[0002] Due to its simple structure, good combustion stability, and strong thrust adjustment capability, the needle-plug injector has become a core component in the field of reusable rocket engines.

[0003] Traditional needle-plug injectors work by radially dividing the propellant into a central path and an outer path. The central path propellant flows through the central channel of the needle plug and is ejected as a radial liquid film or jet after being turned at the end of the injector. The outer path propellant is ejected as an axial liquid film through an annular channel surrounding the central channel and mixes with the central path propellant through collision. However, compared to centrifugal or direct-flow nozzles, existing needle-plug injectors produce larger atomized droplets, resulting in insufficient mixing of the two propellants and poor atomization. In addition, after atomization, the propellant tends to converge towards the central axis region of the combustion chamber, reducing the overall combustion efficiency of the rocket engine.

[0004] In view of the above, this application is hereby submitted. Summary of the Invention

[0005] This application provides a needle-type injector and a rocket engine, aiming to solve at least one of the defects existing in the prior art.

[0006] This application provides a needle-plug injector, comprising: a needle plug body, one end of which is provided with a plurality of radial injection holes for radially injecting a central working fluid; a liquid collection chamber shell, sleeved on the needle plug body and forming an annular injection port with the needle plug body, for axially ejecting an outer ring of working fluid and causing the outer ring of working fluid to collide and mix with the central working fluid ejected from the radial injection holes; and an outward expansion guide structure connected to one end of the needle plug body; wherein the orthographic projection of the annular injection port on one end of the needle plug body along the axial direction is located within the range of the outward expansion guide structure; the plurality of radial injection holes include a plurality of main holes and a plurality of auxiliary holes, the flow area of ​​the main holes is larger than the flow area of ​​the auxiliary holes, the main holes are used to form a first jet capable of penetrating the outer ring of working fluid, and the auxiliary holes are used to form a second jet capable of penetrating the outer ring of working fluid.

[0007] In some embodiments, the main hole and the auxiliary hole are staggered in the axial direction; and / or, the main hole and the auxiliary hole are spaced apart in the circumferential direction; and / or, the main hole is located in the axial direction between the circumferential injection port and the auxiliary hole.

[0008] In some embodiments, the diameter of the end of the outward-expanding flow guide structure that is axially away from the annular slit injection port is larger than the diameter of the end that is close to the annular slit injection port; and / or, the outer peripheral surface of the outward-expanding flow guide structure is an arc-shaped slope or a straight slope.

[0009] In some embodiments, it further includes: an adjustment component connected between the liquid collection chamber housing and the needle plug body, used to adjust the width of the circumferential injection port to change the injection area of ​​the outer ring working fluid.

[0010] In some embodiments, the needle plug body includes a needle plug head and a sleeve fitted onto the needle plug head; the needle plug head forms a central flow channel, one end of the needle plug head is connected to an outward expansion guide structure, and a radial injection hole is provided at one end of the needle plug head near the outward expansion guide structure and communicates with the central flow channel; the liquid collection chamber shell is fitted onto the sleeve, fixedly connected to the needle plug head, and forms an annular injection port between the liquid collection chamber shell and the sleeve; an adjustment component is connected between the liquid collection chamber shell and the sleeve to adjust the relative position of the sleeve and the liquid collection chamber shell along the axial direction to change the width of the annular injection port.

[0011] In some embodiments, the sleeve includes a cylindrical portion fitted onto the needle head and a flange portion extending radially outward from the cylindrical portion. The cylindrical portion extends axially and its diameter gradually decreases at the end facing the outwardly expanding flow guide structure. The liquid collecting chamber housing includes a sleeve portion fitted onto the cylindrical portion and a connecting portion extending radially outward from the sleeve portion. The sleeve portion and the cylindrical portion form an annular slit injection port. A liquid collecting chamber communicating with the annular slit injection port is formed inside the sleeve portion, and an outer ring working fluid inlet communicating with the liquid collecting chamber is provided on the sleeve portion. An adjusting component is axially connected between the flange portion and the connecting portion to adjust the axial distance between the flange portion and the connecting portion.

[0012] In some embodiments, the adjusting assembly includes at least one height adjusting shim and a fastening assembly. The height adjusting shim is disposed between the flange and the connecting portion, and the fastening assembly is axially inserted between the flange, the height adjusting shim, and the connecting portion to lock the flange and the connecting portion in the adjusted axial position.

[0013] In some embodiments, the needle plug body also includes a needle plug head cover, which is connected to the end of the needle plug head away from the outward expansion guide structure, and the needle plug head cover has a central working fluid inlet that communicates with the central flow channel.

[0014] In some embodiments, it also includes multiple axial positioning rods and a positioning flange, the positioning flange being sleeved on the needle plug head and fixedly connected to the needle plug head; the axial positioning rods are axially inserted between the connecting part and the positioning flange, used to connect and fix the liquid collection chamber shell and the needle plug head.

[0015] In some embodiments, at least one first sealing ring is provided at the mating surface between the needle head and the sleeve; at least one second sealing ring is provided at the mating surface between the needle head and the needle head cover; and at least one third sealing ring is provided at the mating surface between the liquid collection chamber housing and the sleeve, wherein the third sealing ring is located axially on the side of the circumferential injection port away from the outward expansion guide structure.

[0016] This application also provides a rocket engine, including the needle-plug injector as described above.

[0017] Compared with the prior art, the needle-plug injector and rocket engine provided in this application have at least the following advantages: The radial injection holes on the needle plug body of this application, used for ejecting the working propellant in the center path, employ a combination design of main holes and auxiliary holes. The difference in flow area between the main holes and auxiliary holes adjusts the radial mixing ratio distribution in the combustion chamber. Specifically, the main hole, with its larger flow area, forms a first jet with a larger flow rate, resulting in larger propellant droplets that can penetrate the outer working propellant and deliver propellant to the far-field region of the combustion chamber. The auxiliary hole, with its smaller flow area, forms a second jet with a smaller flow rate, resulting in smaller propellant droplets that can penetrate the outer working propellant and deliver propellant to the near-center region of the combustion chamber. By mixing the center path working propellant with the outer working propellant in a multi-scale jet manner through multi-level impact mixing, the mixing uniformity of the two working propellants is effectively improved, enhancing the atomization effect.

[0018] Based on the above main and auxiliary hole structure design, this application further sets an outward expansion guide structure at one end of the needle plug body. When the central working fluid is ejected from the radial injection hole and the outer working fluid is ejected from the circumferential injection port and they collide and mix, the resulting mixed flow field is guided by the outward expansion guide structure during its downstream development and generates an outward expansion flow trend, so as to avoid the mixed working fluid from converging towards the central axis area of ​​the combustion chamber, making the atomization field distribution more uniform.

[0019] Therefore, the main and auxiliary hole structure design of this application can provide multi-scale initial jet conditions for the impact mixing of two working fluids, realize the control of radial mixing ratio, and the outward expansion guide structure provides expansion guidance for the two-phase flow field after impact, so that the radial mixing uniformity achieved by the main and auxiliary hole structure can be maintained and continued in the entire flow field, thereby significantly improving the atomization effect and combustion efficiency.

[0020] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0021] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the needle-operated injector provided according to an embodiment of this application; Figure 2 This is an axial cross-sectional view of the needle-operated injector provided according to an embodiment of this application; Figure 3 This is a partial schematic diagram of the radial injection hole provided according to an embodiment of this application; Figure 4 This is a schematic diagram of the external expansion guide structure provided according to an embodiment of this application.

[0023] The attached figures are labeled as follows: 10. Needle-operated injection device; 100. Needle plug body; 110. Needle plug head; 111. Central flow channel; 120. Sleeve; 121. Cylinder section; 122. Flange section; 130. Needle plug head cover; 131. Central working fluid inlet; 140. Axial positioning rod; 150. Positioning flange; R. Radial injection hole; R1. Main hole; R2. Auxiliary hole; 200. Liquid collecting chamber shell; 210. Sleeve part; 211. Liquid collecting chamber; 212. Outer ring working fluid inlet; 220. Connecting part; S. Circumferential injection port; 300. Externally expanded flow guide structure; 400. Adjustment assembly; 410. Height adjustment shim; 420. Fastening assembly; Q1, first sealing ring; Q2, second sealing ring; Q3, third sealing ring. Detailed Implementation

[0024] In the description of this invention, it should be understood that, unless otherwise specified, terms such as “center,” “inner,” “outer,” “axial,” “radial,” and “circumferential” indicating orientation or positional relationship are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention.

[0025] Furthermore, features specified with "first" or "second" for descriptive purposes only should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Features specified with "first" or "second" may explicitly or implicitly include at least one of the specified features. The description of "multiple" generally means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0026] It should be noted that the working medium mentioned in the embodiments of this application is the propellant. For example, the working medium in the center path is the center path propellant, and the working medium in the outer ring is the outer ring propellant. The working medium can be either fuel or oxidizer.

[0027] As mentioned above, in view of the problems of poor atomization effect and easy convergence of working fluid in the central region of the combustion chamber after atomization in the existing needle-plug injector, the inventive concept of this application is to provide a needle-plug injector 10 and a rocket engine. By setting an outward expansion guide structure 300 at one end of the needle-plug body 100, and circumferentially setting multiple radial injection holes R with two flow areas at that end, the radial mixing ratio distribution of the combustion chamber is adjusted and the atomization effect is improved. At the same time, the outward expansion guide structure guides the two-phase flow field after impact to expand outward and avoids the working fluid from converging towards the center, thereby achieving a synergistic improvement in atomization effect and flow field uniformity.

[0028] It should be understood that in practical applications, the combustion chamber of the rocket engine can be located at one axial end of the needle-plug injector 10.

[0029] Based on the above concept, and referring to Figures 1-4 As shown, this application embodiment provides a needle-plug injector 10, including: a needle-plug body 100, one end of which is provided with a plurality of radial injection holes R for radially injecting the central working fluid; a liquid collection chamber shell 200, sleeved on the needle-plug body 100, and forming an annular injection port S between the needle-plug body 100 and the needle-plug body 100, for axially ejecting the outer ring working fluid and causing the outer ring working fluid to collide and mix with the central working fluid ejected from the radial injection holes R; and an outward expansion guide structure 300 connected to one end of the needle-plug body 100; wherein, the orthographic projection of the annular injection port S along the axial direction at one end of the needle-plug body 100 is located within the range of the outward expansion guide structure 300; the plurality of radial injection holes R include a plurality of main holes R1 and a plurality of auxiliary holes R2, the flow area of ​​the main holes R1 is larger than the flow area of ​​the auxiliary holes R2, the main holes R1 are used to form a first jet that can penetrate the outer ring working fluid, and the auxiliary holes R2 are used to form a second jet that can penetrate the outer ring working fluid.

[0030] It can be understood that the needle-bolt injector 10 is mainly composed of a needle-bolt body 100 and a liquid collection chamber shell 200. The needle-bolt body 100 has an outer expansion guide structure 300 at one end as the injection end, and multiple radial injection holes R are arranged circumferentially, so that the central working fluid can be injected radially. The liquid collection chamber shell 200 and the needle-bolt body 100 form an annular injection port S. The annular injection port S can spray the outer ring working fluid along the axial direction, and make the outer ring working fluid collide and mix with the central working fluid sprayed from the radial injection holes R. Since the orthogonal projection of the annular injection port S along the axial direction at one end of the needle-bolt body 100 is within the range of the outer expansion guide structure 300, it can ensure the effective coverage of the expansion guide effect, and cause the mixed working fluid to generate an outward expansion flow tendency under the guidance of the outer expansion guide structure 300, thereby avoiding the mixed working fluid from converging towards the central axis area of ​​the combustion chamber, and making the atomization field distribution more uniform.

[0031] Furthermore, since the multiple radial injection holes R include multiple main holes R1 and multiple auxiliary holes R2, the flow area of ​​the main holes R1 is larger than that of the auxiliary holes R2. This difference in flow area between the main holes R1 and the auxiliary holes R2 causes the working fluid in the center path to be ejected in two jet forms with different momentum and scale. Specifically, in terms of droplet size, the flow area of ​​the auxiliary holes R2 is smaller, resulting in smaller droplet size in the second jet, which is easier to mix and evaporate; the flow area of ​​the main holes R1 is larger, resulting in larger droplet size in the first jet, requiring a longer path to complete mixing and evaporation, and enabling effective propellant delivery to the far-field region of the combustion chamber. In terms of the combined momentum angle, the flow area of ​​the auxiliary holes R2 is smaller, resulting in a relatively smaller momentum ratio between the second jet ejected from them and the outer working fluid, leading to a smaller combined jet momentum angle, and the jet tends to develop towards the near-center region; the flow area of ​​the main holes R1 is larger, resulting in a relatively larger momentum ratio between the first jet ejected from them and the outer working fluid, leading to a larger combined jet momentum angle, and the jet can develop towards a more distant radial region. Regarding the control of the mixing ratio, the auxiliary orifice R2, due to its smaller flow area and momentum, results in a relatively higher proportion of the outer working fluid in the composite jet formed with the outer working fluid. Conversely, the main orifice R1, with its larger flow area and momentum, results in a relatively higher proportion of the central working fluid in the composite jet formed with the outer working fluid. Thus, the multi-scale jet formed by the main orifice R1 and the auxiliary orifice R2, along with the multi-level impact mixing of the outer working fluid, not only achieves multi-scale atomization at the droplet scale but also provides gradient control over jet momentum and mixing ratio distribution. This enables the central working fluid and the outer working fluid to achieve multi-level, wide-range impact mixing in the radial direction of the combustion chamber, effectively improving the mixing ratio distribution of the two working fluids in the radial direction of the combustion chamber and significantly enhancing the atomization effect.

[0032] Therefore, the main and auxiliary hole structure design of the needle plug body 100 provides multi-scale initial jet conditions for impact mixing and realizes the initial control of radial mixing ratio. Meanwhile, the outward expansion guide structure 300 provides expansion guidance for the two-phase flow field after impact, so that the radial mixing uniformity achieved by the main and auxiliary hole structure can be maintained and continued in the entire flow field. The two work together to achieve a dual improvement in atomization effect and flow field uniformity.

[0033] In some embodiments, the main hole R1 and the auxiliary hole R2 are staggered in the axial direction. For example, the main hole R1 can be located axially behind the auxiliary hole R2 (i.e., further away from the outer expansion guide structure 300) or axially in front of the auxiliary hole R2 (i.e., closer to the outer expansion guide structure 300), so that the working fluid in the center path forms a layered jet distribution in the axial direction, further optimizing the impact mixing effect with the outer working fluid.

[0034] In some embodiments, the main holes R1 and auxiliary holes R2 are arranged at intervals in the circumferential direction. For example, multiple main holes R1 and multiple auxiliary holes R2 can be arranged alternately in the circumferential direction or arranged according to other interval rules, so that the working fluid in the central path forms a uniform jet distribution in the circumferential direction and improves the circumferential uniformity of the atomization field.

[0035] In some embodiments, the main hole R1 and the auxiliary hole R2 are staggered in the axial direction and spaced apart in the circumferential direction. This composite arrangement enables the working fluid in the center path to form a more complex jet distribution in three-dimensional space, achieving multi-dimensional and multi-level impact mixing with the working fluid in the outer ring, thereby further improving the atomization effect.

[0036] In some embodiments, the main orifice R1 is located axially between the annular jet nozzle S and the auxiliary orifice R2, which allows the first jet formed by the main orifice R1 to be closer to the outer working fluid ejected from the annular jet nozzle S, thereby enhancing the penetration effect. At the same time, the second jet formed by the auxiliary orifice R2 is relatively far away from the annular jet nozzle S, which is beneficial for delivering propellant to the near-center region.

[0037] refer to Figure 3 As shown, in one specific embodiment, the main hole R1 is arch-shaped, and the auxiliary hole R2 is a round hole.

[0038] Furthermore, multiple main holes R1 are aligned circumferentially to form a main injection ring, and multiple auxiliary holes R2 are aligned circumferentially to form an auxiliary injection ring. The main injection ring and the auxiliary injection ring are staggered axially, with the auxiliary injection ring closer to the outward expansion guide structure 300 and the main injection ring relatively farther away from the outward expansion guide structure 300. Simultaneously, the main holes R1 and auxiliary holes R2 are alternately arranged circumferentially, thus forming a radial injection array with alternating main holes R1 and auxiliary holes R2. The working fluid in the center path flows in from the rear end of the needle plug body 100 (the end farther from the outward expansion guide structure 300) and flows towards the front end along the central flow channel 111. During the flow process, the working fluid first reaches the main injection ring, forming a first jet through the main orifice R1. This jet penetrates the outer working fluid with greater momentum, releasing larger droplets into the far-field region of the combustion chamber. The working fluid then continues flowing forward to the auxiliary injection ring, forming a second jet through the auxiliary orifice R2. This second jet penetrates the outer working fluid with less momentum, releasing smaller droplets into the near-center region of the combustion chamber. Because the main orifice R1 and auxiliary orifice R2 are arranged alternately in the circumferential direction, the two jet sizes are evenly distributed on the same axial cross-section of the combustion chamber, resulting in a more thorough and uniform impact mixing with the outer working fluid. This composite injection structure, with the main injection ring behind and the auxiliary injection ring in front, and alternating circumferentially, allows the working fluid in the center path to undergo multi-level impact mixing with the outer working fluid in a first-to-last-penetration sequence. This further optimizes the radial mixing ratio distribution in the combustion chamber and significantly improves the atomization effect.

[0039] In some embodiments, the diameter of the end of the outward-expanding flow guiding structure 300 that is axially away from the annular slit injection port S is larger than the diameter of the end that is close to the annular slit injection port S. The outward-expanding flow guiding structure 300 is radially outward-expanding. This outward-expanding configuration can provide an outward-expanding flow guiding surface for the two-phase flow field after impact, guiding the mixed working fluid to develop towards the radially outer region of the combustion chamber, thereby effectively preventing the working fluid from converging towards the central axis.

[0040] refer to Figure 4 As shown, in some embodiments, the outer peripheral surface of the outwardly expanding flow guiding structure 300 is an arc-shaped slope (e.g., Figure 4 (as shown in (a)). The curved slope makes the guiding surface smoother, reduces flow resistance, and allows the mixed working fluid to maintain a stable flow state during expansion.

[0041] Continue to refer to Figure 4 As shown, in some embodiments, the outer peripheral surface of the outwardly expanding flow guiding structure 300 is a straight inclined surface (e.g., Figure 4 (b) shows that it is more conducive to reducing flow resistance.

[0042] In some variations, the outward-expanding flow guide structure 300 can be a hemispherical head with an arc-shaped inclined surface on its outer circumferential surface. The diameter of the end away from the annular slit injection port S along the axial direction is larger than the diameter of the end close to the annular slit injection port S, forming an outward-expanding configuration.

[0043] Continue to refer to Figure 1 and Figure 2 As shown, to adjust the injection area of ​​the outer working fluid, in some embodiments, the needle-plug injector 10 further includes an adjustment component 400 connected between the liquid collection chamber housing 200 and the needle plug body 100, used to adjust the width of the annular slit injection port S. The adjustment component 400 can change the injection area and flow rate of the outer working fluid by adjusting the width of the annular slit injection port S, thereby adjusting the momentum ratio and mixing ratio of the outer working fluid and the central working fluid, enabling the needle-plug injector 10 to adapt to the combustion organization requirements under different operating conditions. For example, during rocket engine thrust adjustment, the mixing effect of the two working fluids can be optimized by adjusting the width of the annular slit injection port S, ensuring combustion efficiency and combustion stability.

[0044] In some embodiments, the needle plug body 100 includes a needle plug head 110 and a sleeve 120 sleeved on the needle plug head 110; the needle plug head 110 forms a central flow channel 111, one end of the needle plug head 110 is connected to an outward expansion guide structure 300, and a radial injection hole R is disposed at one end of the needle plug head 110 near the outward expansion guide structure 300 and communicates with the central flow channel 111; the liquid collection chamber housing 200 is sleeved on the sleeve 120, fixedly connected to the needle plug head 110, and forms an annular injection port S between the sleeve 120 and the sleeve 120; the adjustment component 400 is connected between the liquid collection chamber housing 200 and the sleeve 120, and is used to adjust the relative position of the sleeve 120 and the liquid collection chamber housing 200 along the axial direction to change the width of the annular injection port S.

[0045] like Figure 2 As shown in this embodiment, a central flow channel 111 is formed inside the needle head 110. The needle head 110 includes a front section and a rear section along the axial direction. The diameter of the front section is smaller than the diameter of the rear section. The sleeve 120 is sleeved on the front section of the needle head 110. Since the liquid collecting chamber housing 200 is sleeved on the sleeve 120 and fixedly connected to the needle head 110, the liquid collecting chamber housing 200 and the sleeve 120 form an annular injection port S. The outer working fluid is ejected axially through the annular injection port S between the liquid collecting chamber housing 200 and the sleeve 120. The adjusting component 400 is connected between the liquid collecting chamber housing 200 and the sleeve 120. Under the action of the adjusting component 400, the axial relative position between the sleeve 120 and the liquid collecting chamber housing 200 can be adjusted, and the width of the corresponding annular injection port S changes accordingly, thereby realizing the adjustment of the width of the annular injection port S. By setting the adjustment component 400 between the liquid collection chamber housing 200 and the sleeve 120, and using the relative axial displacement between the sleeve 120 and the liquid collection chamber housing 200 to change the circumferential gap width, the adjustment of the circumferential gap injection port S is made more precise and reliable.

[0046] In some embodiments, the sleeve 120 includes a cylindrical portion 121 sleeved on the needle head 110 and a flange portion 122 extending radially outward based on the cylindrical portion 121. The cylindrical portion extends axially and its diameter gradually decreases at one end facing the outward expansion guide structure 300. The liquid collection chamber housing 200 includes a sleeve portion 210 sleeved on the cylindrical portion 121 and a connecting portion 220 extending radially outward based on the sleeve portion 210. The sleeve portion 210 and the cylindrical portion 121 form an annular injection port S. A liquid collection chamber 211 communicating with the annular injection port S is formed inside the sleeve portion 210, and an outer working fluid inlet 212 communicating with the liquid collection chamber 211 is provided on the sleeve portion 210. The adjusting component 400 is axially connected between the flange portion 122 and the connecting portion 220 to adjust the axial distance between the flange portion 122 and the connecting portion 220.

[0047] In this embodiment, the cylindrical portion 121 of the sleeve 120 is sleeved on the front section of the needle plug head 110. The diameter of the end of the cylindrical portion 121 facing the outward expansion guide structure 300 gradually decreases, forming a conical structure, so as to form an annular injection port S with the liquid collection chamber shell 200, and at the same time, it is conducive to the flow of working fluid. The flange portion 122 extends radially outward based on the end of the cylindrical portion 121 away from the outward expansion guide structure 300, forming an annular flange structure. The liquid collecting chamber shell 200 includes a sleeve portion 210 and a connecting portion 220. The sleeve portion 210 is sleeved on the cylindrical portion 121, and the conical structure formed with the cylindrical portion 121 surrounds the annular slit injection port S. A liquid collecting chamber 211 is formed inside the sleeve portion 210. A radial through hole is opened on the inner side of the liquid collecting chamber 211 to realize the connection between the liquid collecting chamber 211 and the annular slit injection port S. An outer ring working fluid inlet 212 is opened on the sleeve portion 210. The outer ring working fluid inlet 212 is connected to the liquid collecting chamber 211. The outer ring working fluid enters the liquid collecting chamber 211 through the outer ring working fluid inlet 212 and is then sprayed out axially through the annular slit injection port S.

[0048] In this embodiment, the connecting part 220 extends radially outward from the end of the sleeve part 210 away from the annular injection port S, forming an annular flange structure corresponding to the flange part 122. The adjusting component 400 is axially connected between the flange part 122 and the connecting part 220 to form two annular flange structures. Through the adjusting action of the adjusting component 400, the flange part 122 can be displaced axially, thereby changing the axial distance between the flange part 122 and the connecting part 220. When the axial distance between the flange part 122 and the connecting part 220 changes, the relative axial position between the sleeve 120 and the liquid collection chamber housing 200 changes accordingly, thereby realizing the adjustment of the width of the annular injection port S.

[0049] The adjusting component 400 in this application embodiment can be implemented in various structural forms. For example, in some embodiments, the adjusting component 400 may include a shim group, and the width of the circumferential injection port S can be adjusted by increasing or decreasing the number of shims or by replacing shims of different thicknesses. In other embodiments, the adjusting component 400 may adopt a threaded adjusting structure, and the width of the circumferential injection port S can be continuously adjusted by rotating the adjusting nut or other means.

[0050] refer to Figure 2 In some embodiments, the adjustment assembly 400 includes at least one height adjustment shim 410 and a fastening assembly 420. The height adjustment shim 410 is disposed between the flange portion 122 and the connecting portion 220, and the fastening assembly 420 is axially inserted between the flange portion 122, the height adjustment shim 410 and the connecting portion 220 to lock the flange portion 122 and the connecting portion 220 in the adjusted axial position.

[0051] Since the height adjusting shim 410 is located between the flange 122 and the connecting part 220, the axial distance between the flange 122 and the connecting part 220 can be precisely adjusted by selecting different thicknesses or numbers of height adjusting shims 410, thereby achieving adjustment of the circumferential injection port S width. The fastening assembly 420 is axially inserted between the flange 122, the height adjusting shim 410, and the connecting part 220. The fastening assembly 420 may include, for example, a bolt and a nut. The bolt passes sequentially through the flange 122, the height adjusting shim 410, and the connecting part 220, and then engages with the nut to lock the flange 122 and the connecting part 220 in the adjusted axial position. Thus, by increasing or decreasing the number of shims or replacing shims of different thicknesses, the circumferential width can be adjusted in stages. The fastening assembly ensures the stability of the adjusted position, enabling the needle-operated injector 10 to operate stably at the required circumferential width for a long period.

[0052] In some embodiments, the needle plug body 100 further includes a needle plug head cover 130, which is connected to the end of the needle plug head 110 away from the outward expansion guide structure 300. The needle plug head cover 130 has a central working fluid inlet 131 communicating with the central flow channel 111. The needle plug head cover 130 and the end of the needle plug head 110 away from the outward expansion guide structure 300 can be fixed together by threaded connection, flange connection, or other suitable connection methods, and a sealing structure can be provided as needed to ensure sealing. The top of the needle plug head cover 130 has a central working fluid inlet 131, which communicates with the central flow channel 111 formed inside the needle plug head 110. The central working fluid enters the needle plug head cover 130 through the central working fluid inlet 131, then flows into the central flow channel 111, and finally exits through the radial injection hole R.

[0053] In some embodiments, the needle plug body 100 further includes a plurality of axial positioning rods 140 and a positioning flange 150. The positioning flange 150 is sleeved on the needle plug head 110 and fixedly connected to the needle plug head 110. The axial positioning rods 140 are axially inserted between the connecting part 220 and the positioning flange 150 for connecting and fixing the liquid collection chamber housing 200 and the needle plug head 110.

[0054] A positioning flange 150 is fitted onto the needle plug head 110, fixedly connected to the front section of the needle plug head 110, and in contact with the rear end face of the needle plug head 110. Exemplarily, the positioning flange 150 can be connected to the needle plug head 110 by welding, threaded connection, or other suitable fixing methods to ensure stable relative positioning between the two. Multiple axial positioning rods 140 (e.g., four) are circumferentially spaced around the positioning flange, each axial positioning rod 140 passing axially between the connecting portion 220 of the liquid collection chamber housing 200 and the positioning flange 150. One end of the axial positioning rod 140 is connected to the connecting portion 220, and the other end is connected to the positioning flange 150, thereby connecting and fixing the liquid collection chamber housing 200 and the needle plug head 110 together to prevent displacement of the liquid collection chamber housing 200 when the adjusting assembly 400 adjusts the width of the circumferential injection port S. Thus, by setting the axial positioning rods 140 and the positioning flange 150, on the one hand, the relative positional accuracy between the liquid collection chamber housing 200 and the needle plug head 110 is ensured, so that the width of the circumferential injection port S remains uniform in the circumferential direction; on the other hand, this connection structure enhances the overall rigidity of the needle plug injector 10, enabling it to withstand large loads during operation without deformation, ensuring long-term reliability and stability. Simultaneously, the multiple axial positioning rods 140 are evenly arranged circumferentially, resulting in a more uniform distribution of connection force and further improving structural stability.

[0055] In some embodiments, at least one first sealing ring Q1 is provided at the mating surface between the needle head 110 and the sleeve 120 to seal the gap between the needle head 110 and the sleeve 120 and prevent the working fluid from leaking from the mating surface.

[0056] Furthermore, at least one second sealing ring Q2 is provided at the mating surface between the needle head 110 and the needle head cover 130. The second sealing ring Q2 is used to seal the connection between the needle head 110 and the needle head cover 130 to prevent the working fluid in the center path from leaking from the connection.

[0057] Furthermore, at least one third sealing ring Q3 is provided at the mating surface between the liquid collecting chamber housing 200 and the sleeve 120, and the third sealing ring Q3 is located axially on the side of the annular slit injection port S away from the outward expansion guide structure 300. The third sealing ring Q3 is used to seal the gap between the liquid collecting chamber housing 200 and the sleeve 120 except for the annular slit injection port S, preventing the outer ring working fluid from leaking out of the annular slit injection port S. Setting the third sealing ring Q3 on the side of the annular slit injection port S away from the outward expansion guide structure 300, that is, at the axial rear end of the annular slit injection port S, can avoid the sealing ring interfering with the flow of the working fluid at the annular slit injection port S, and at the same time ensure that the outer ring working fluid will not leak before entering the annular slit injection port S. By setting the above sealing ring, the sealing performance of the connection points of each component of the needle-plug injector 10 is effectively guaranteed, avoiding energy loss and combustion instability caused by working fluid leakage, and improving the overall reliability and safety of the machine.

[0058] This application also provides a rocket engine, including the needle-plug injector 10 as described above.

[0059] In summary, the main and auxiliary orifice structure design of the needle-plug injector 10 in this application embodiment can provide multi-scale initial jet conditions for the impact mixing of two working fluids, and realize the initial control of the radial mixing ratio. The outward expansion guide structure at one end of the needle-plug injector 10 provides expansion guidance for the two-phase flow field after impact, so that the radial mixing uniformity achieved by the main and auxiliary orifice structure can be maintained and continued in the entire flow field, thereby significantly improving the atomization effect and combustion efficiency.

[0060] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A needle-type injection device, characterized in that, include: The needle plug body (100) has multiple radial injection holes (R) circumferentially arranged at one end for injecting the working fluid in the center path radially. The liquid collection chamber housing (200) is sleeved on the needle plug body (100) and forms an annular injection port (S) between the housing and the needle plug body (100), for axially ejecting the outer ring working fluid and causing the outer ring working fluid to collide and mix with the central working fluid ejected from the radial injection hole (R); and An externally expanding flow guiding structure (300) is connected to one end of the needle plug body (100); Wherein, the orthographic projection of the circumferential injection port (S) along the axial direction at one end of the needle plug body (100) is located within the range of the outward expansion guide structure (300); The plurality of radial injection holes (R) include a plurality of main holes (R1) and a plurality of auxiliary holes (R2), wherein the flow area of ​​the main holes (R1) is greater than the flow area of ​​the auxiliary holes (R2), the main holes (R1) are used to form a first jet capable of penetrating the outer ring working fluid, and the auxiliary holes (R2) are used to form a second jet capable of penetrating the outer ring working fluid.

2. The needle-plug injection device according to claim 1, characterized in that, The main hole (R1) and the auxiliary hole (R2) are staggered in the axial direction; And / or, the main hole (R1) and the auxiliary hole (R2) are arranged at intervals in the circumferential direction; And / or, the main hole (R1) is located in the axial direction between the circumferential injection port (S) and the auxiliary hole (R2).

3. The needle-plug injection device according to claim 1, characterized in that, The diameter of the end of the outwardly expanding flow guiding structure (300) that is axially away from the annular slit injection port (S) is larger than the diameter of the end that is close to the annular slit injection port (S); And / or, the outer peripheral surface of the outward expansion guide structure (300) is an arc-shaped inclined surface or a straight inclined surface.

4. The needle-plug injection device according to any one of claims 1 to 3, characterized in that, Also includes: An adjustment component (400) is connected between the liquid collection chamber housing (200) and the needle plug body (100) to adjust the width of the circumferential injection port (S) to change the injection area of ​​the outer ring working fluid.

5. The needle-plug injection device according to claim 4, characterized in that, The needle plug body (100) includes a needle plug head (110) and a sleeve (120) sleeved on the needle plug head (110). The needle head (110) has a central flow channel (111), one end of the needle head (110) is connected to the outward expansion guide structure (300), and the radial injection hole (R) is disposed at one end of the needle head (110) near the outward expansion guide structure (300) and communicates with the central flow channel (111). The liquid collection chamber housing (200) is sleeved on the sleeve (120), fixedly connected to the needle head (110), and forms the annular injection port (S) between the housing and the sleeve (120). The adjustment component (400) is connected between the liquid collection chamber housing (200) and the sleeve (120) to adjust the relative position of the sleeve (120) and the liquid collection chamber housing (200) along the axial direction, so as to change the width of the annular injection port (S).

6. The needle-plug injection device according to claim 5, characterized in that, The sleeve (120) includes a cylindrical part (121) sleeved on the needle head (110) and a flange part (122) extending radially outward based on the cylindrical part (121). The cylindrical part extends axially and the diameter of one end facing the outward expansion guide structure (300) gradually decreases. The liquid collection chamber housing (200) includes a sleeve portion (210) sleeved on the cylindrical portion (121) and a connecting portion (220) extending radially outward based on the sleeve portion (210). The sleeve portion (210) and the cylindrical portion (121) form the annular slit injection port (S). A liquid collection chamber (211) communicating with the annular slit injection port (S) is formed in the sleeve portion (210), and an outer ring working fluid inlet (212) communicating with the liquid collection chamber (211) is provided on the sleeve portion (210). The adjustment assembly (400) is axially connected between the flange (122) and the connecting part (220) to adjust the axial distance between the flange (122) and the connecting part (220).

7. The needle-plug injection device according to claim 6, characterized in that, The adjusting assembly (400) includes at least one height adjusting shim (410) and a fastening assembly (420). The height adjusting shim (410) is disposed between the flange portion (122) and the connecting portion (220). The fastening assembly (420) is axially inserted between the flange portion (122), the height adjusting shim (410), and the connecting portion (220) to lock the flange portion (122) and the connecting portion (220) in the adjusted axial position.

8. The needle-plug injection device according to claim 5, characterized in that, The needle plug body (100) also includes a needle plug head cover (130), which is connected to the end of the needle plug head (110) away from the outward expansion guide structure (300). The needle plug head cover (130) has a central working fluid inlet (131) that communicates with the central flow channel (111).

9. The needle-plug injection device according to claim 6, characterized in that, It also includes multiple axial positioning rods (140) and a positioning flange (150), the positioning flange (150) being sleeved on the needle head (110) and fixedly connected to the needle head (110); The axial positioning rod (140) is axially inserted between the connecting part (220) and the positioning flange (150) to connect and fix the liquid collection chamber housing (200) and the needle plug head (110).

10. A rocket engine, characterized in that, Includes the needle-plug injection device (10) as described in any one of claims 1 to 9.

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