Gas-liquid pintle injector for strengthening spray combustion through forward and reverse rotational flow and cooling head of pintle rod of gas-liquid pintle injector

Abstract

To provide a gas-liquid pintle injector for cooling a head of a pintle rod of the gas-liquid pintle injector.SOLUTION: The gas-liquid pintle injector is provided with: a pintle rod 1; and an inner sleeve 2 and an outer sleeve 3 which are coaxially and sequentially arranged are arranged on a periphery of the pintle rod 1. Also, the pintle rod 1 is provided with, in a head end face thereof, an injection hole 11 having an ultra-small hole diameter. The pintle rod 1 provides a liquid non-rotational flow, and the inner sleeve 2 and the outer sleeve 3 provide gas rotational flows. The inner sleeve 2 and the outer sleeve 3A are arranged with two radial multi-layer rotational flow structures whose rotational flow directions are opposite to each other so as to form a gas phase rotational flow with a layer divided into an inner side and an outer side. The inner side of the gas-liquid rotational flow collides with a liquid jet of the head of the pintle rod 1 in a radial direction to strengthen spraying, and the outer side of the gas rotational flow reduces non-uniformity of the atomization of spraying. A steam heat air absorption action of a liquid droplet from the ultra-small hole diameter injection hole 11 by injection atomization protects the pintle from being ablated.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present application relates to the technical field of recoverable variable flow rate adjustable rocket propulsion equipment, and more particularly to a gas-liquid pintle injector that uses forward and reverse swirling flows to enhance spray combustion and cool the head of the pintle rod of the gas-liquid pintle injector. [Background technology]

[0002] The present invention relates to rocket propulsion technology, and is a gas / liquid pintle injector that uses gas / liquid injection of fuel, particularly suitable for long-term storable environmentally friendly room temperature fuel systems (such as hydrogen peroxide / kerosene, nitrous oxide / propane), avoids the complexity of systems that use low-temperature liquid oxygen fuel, meets the current development requirements for small flow rate rockets, and uses multi-layer swirling flow for spray cooling of the injector head to enhance spray combustion. The pintle injector is a suitable choice for known rocket variable thrust due to a series of advantages such as its simple structure, continuous flow rate adjustment, and combustion stability.

[0003] Gas / liquid injection (generally, gas is injected in the axial direction) has an advantage over liquid / liquid injection in that the shearing action of the gas injected at high speed can more easily break up the liquid fuel jet. The prior granted patent, "Gas / liquid pintle injector with swirling flow to assist atomization and adjustable degree of swirl," describes an improvement over the conventional (axial) gas / (radial) liquid pintle injector that effectively solves the poor spray distribution characteristics caused by the conventional gas / liquid pintle injector's excessively high axial gas injection speed, and employs swirling flow injection for the axial gas, reducing the axial momentum and increasing the cone angle of the spray, while utilizing the circumferential shearing action of the swirling flow to improve atomization. At the same time, by rationally distributing the respective flow rates according to the axial flow paths formed by the inner sleeve and the outer sleeve, the degree of gas swirl can be adjusted, optimal spray cone angle and atomization characteristics can be achieved, and the matching requirements for the structural parameter design of the spray area and spray speed can be simplified. Furthermore, by utilizing the central gas core low-pressure area formed by the gas swirl, part of the radial liquid jet can be drawn into the outer sleeve, promoting the breakup of the root of the jet, and assisting atomization by the gas.

[0004] However, the invention has the following shortcomings in principle design, structural design, and application design in actual combustion chamber scenes: First, the axial swirling gas adopts a single tangential hole inlet, and the swirling flow only has one rotation direction. When the axial length of the pintle or the axial flow path of the gas is not long enough, the swirling flow in the pipe does not progress sufficiently, and the gas velocity is not uniform in the circumferential direction of the annular gap outlet. As a result, after the gas collides with the radial jet of the pintle head, the spray shape will be non-axisymmetric and non-uniform in spatial distribution, which will affect the spray combustion in the combustion chamber; Second, the use of swirling gas to assist atomization improves the spray characteristics, but reduces the radial and axial breakup distances of the jet, bringing the high-concentration spray region and the subsequent spray combustion region closer to the pintle head, making the pintle head more susceptible to ablation and affecting its service life. Summary of the Invention [Problem to be solved by the invention]

[0005] In response to the shortcomings of the prior art, the present invention provides a gas-liquid pintle injector that uses forward and reverse swirling flows to strengthen spray combustion and cool the head of the pintle rod of the gas-liquid pintle injector. The first objective is to solve the problem in the prior art that the unidirectional swirling gas collides with the radial jet of the pintle rod head, resulting in a spray pattern that is non-axisymmetric and non-uniform in spatial distribution, which has a negative impact on the spray combustion in the combustion chamber. The second objective is to solve the problem that the radial and axial breakup distance of the jet is reduced, causing the high spray concentration region and the subsequent spray combustion region to approach the pintle rod head, making the pintle head more susceptible to ablation and affecting its service life. [Means for solving the problem]

[0006] The present application adopts the following technical solutions to solve the technical problems: A gas-liquid pintle injector for cooling a head of a pintle rod of the gas-liquid pintle injector by strengthening spray combustion with forward and reverse swirling flows, the gas-liquid pintle injector being used in a rocket propulsion system, the gas-liquid pintle injector being provided with a pintle rod, an inner sleeve and an outer sleeve which are coaxially arranged around the outer periphery of the pintle rod, the pintle rod being used to provide a non-swirling flow of liquid, and the inner sleeve and the outer sleeve being used to provide a swirling flow of gas; Two radial multi-layer swirling flows with opposite swirling directions are arranged within the inner sleeve and the outer sleeve, thereby forming a gas-phase swirling flow structure with inner and outer layers. The inner side of the gas-phase swirling flow collides with the radial liquid jet from the pintle rod head, strengthening the spray, and the outer side of the gas-phase swirling flow can reduce the circumferential non-uniformity of the atomization of the spray. Ultra-small diameter injection holes are opened on the end surface of the pintle rod head, and the atomized droplets formed by being injected from the ultra-small diameter injection holes protect the pintle from ablation by the evaporation heat absorption action. The radial liquid jet from the pintle rod head is ejected from injection holes with rectangular opening shapes arranged in a circumferential array on the pintle rod head.

[0007] Furthermore, a pintle rod internal passage is opened at the center of the pintle rod, an inner sleeve internal passage is opened between the pintle rod and the inner sleeve, and an outer sleeve internal passage is provided between the inner sleeve and the outer sleeve, the outlet ends of the inner sleeve internal passage and the outer sleeve internal passage are at the same height, and the outlet end of the pintle rod internal passage protrudes a set distance outside the outlet ends of the inner sleeve internal passage and the outer sleeve internal passage.

[0008] Furthermore, the outlet end of the pintle rod inner passage protrudes a set distance outside the outlet ends of the inner sleeve inner passage and the outer sleeve inner passage, and the set distance is equal to the outer diameter of the pintle rod, preferably 12 mm, but is not limited to this.

[0009] Furthermore, the gas-liquid pintle injector includes three parts, which are a pintle rod 1, an inner sleeve, and an outer sleeve, in the axial direction, in that order from top to bottom. The pintle rod is provided with a liquid radial inlet and a radial inlet liquid collection chamber for providing a non-swirling flow of liquid, and the radial inlet liquid collection chamber is connected to the pintle rod inner flow path. The inner sleeve is provided with a gas positive swirling tangential inlet and a positive swirling tangential inlet collection chamber for providing a swirling flow of gas, and the positive swirling tangential inlet collection chamber is a gas phase swirling inlet having an inner and outer layer. The pintle rod is connected to an inner sleeve internal flow path on the inside of the swirling structure, and the outer sleeve is provided with a gas reverse swirling tangential inlet and a reverse swirling tangential inlet collection chamber for providing a swirling flow of gas, and the reverse swirling tangential inlet collection chamber is connected to an outer sleeve internal flow path on the outside of the gas-phase swirling flow structure separated into inner and outer layers, and the pintle rod and the inner sleeve, and the inner sleeve and the outer sleeve are respectively connected by flanges, and the forward rotation means rotating in a clockwise direction when viewed in a plane, and the reverse rotation means rotating in a counterclockwise direction when viewed in a plane.

[0010] Furthermore, the gas phase swirling flow structure having inner and outer layers with opposite swirling flow directions comprises a pintle rod, an inner sleeve, an outer sleeve, a gas positive swirl tangential inlet and a positive swirl tangential inlet collection chamber opened in the inner sleeve, a gas reverse swirl tangential inlet and a reverse swirl tangential inlet collection chamber opened in the outer sleeve, an inner sleeve flow path between the pintle rod and the inner sleeve, and an outer sleeve flow path between the inner sleeve and the outer sleeve, and the gas positive swirl tangential inlet and the gas reverse swirl tangential inlet have tangential inlets that are parallel to each other and have opposite directions.

[0011] Furthermore, the length of the flow passage in the pintle rod is preferably, but not limited to, 80 to 100 mm, the length of the flow passage in the inner sleeve is preferably, but not limited to, 65 to 75 mm, and the length of the flow passage in the outer sleeve is preferably, but not limited to, 50 to 60 mm.

[0012] Furthermore, the gas-liquid pintle injector injects with a two-component propellant, which is divided into a liquid propellant A and a gas propellant B. The pintle rod inner passage is connected to the supply system of the liquid propellant A via the liquid radial inlet, and the inner sleeve inner passage and the outer sleeve inner passage are connected to the gas propellant via a gas forward swirl tangential inlet and a gas reverse swirl tangential inlet, respectively.

[0013] Furthermore, the jet speed of the outlet airflow of the inner sleeve inner flow passage is preferably, but not limited to, 150 to 250 m / s, the jet speed of the outlet airflow of the outer sleeve inner flow passage is preferably, but not limited to, 150 to 250 m / s, and the liquid jet speed of the jet hole having a rectangular opening shape at the outlet of the pintle rod inner flow passage is preferably, but not limited to, 20 to 40 m / s.

[0014] Furthermore, ultra-small injection holes are opened on the end surface of the head of the pintle rod, and the ultra-small injection holes are uniformly distributed in the circumferential direction of each set radius, and the number of small holes distributed in the circumferential direction of each radius is equal.

[0015] Furthermore, the number and diameter of the ultra-small injection holes on the end surface of the head of the pintle rod are determined based on the criteria of not excessively consuming or affecting the mass flow rate of the liquid propellant A, while at the same time fulfilling the evaporation heat absorption function of the droplets to protect the pintle from ablation. The diameter of the ultra-small injection holes on the end surface of the head of the pintle rod is preferably 0.06 to 0.1 mm, but is not limited thereto. Effect of the Invention

[0016] The present invention organically combines and depends on a design with two opposite swirling flows and a design with injection holes at the pintle head, aiming to achieve more sufficient and spatially uniformly distributed atomization with the design with two opposite swirling flows, and ensures that the design with injection holes at the pintle head achieves the goal of protecting the head of the pintle rod from abrasion after sufficient atomization, thereby solving the problem in the prior art that the spray pattern caused by the collision of the unidirectional swirling gas with the radial jet at the pintle head exhibits non-axisymmetric and non-uniform spatial distribution, which adversely affects the spray combustion in the combustion chamber, and also solves the problem that the radial and axial breakup distance of the jet is reduced, which brings the spray high concentration area and the subsequent spray combustion area closer to the pintle head, making the pintle head more susceptible to abrasion and affecting its service life. In essence, by implementing this invention, it is possible to dramatically improve the combustion condition in a gas-liquid pintle injector for rockets by greatly promoting atomization, which also includes the prevention of the occurrence of combustion oscillation, and further to protect the injector head from ablation burn damage and drastically improve durability and reliability, all of which can be achieved at the same time. [Brief description of the drawings]

[0017] [Figure 1] FIG. 2 is a schematic diagram of an assembly diagram of the gas-liquid pintle injector of the present application from a first perspective. [Figure 1a] FIG. 1 is a schematic diagram of a division of five cross sections of an assembly drawing from a first perspective. [Figure 1b1] FIG. 1b is a two-dimensional view of the AA liquid radial inlet cross section of FIG. [Figure 1b2] FIG. 1b is a three-dimensional view of the AA liquid radial inlet cross section of FIG. [Figure 1c1] FIG. 1b is a two-dimensional view of the BB gas positive swirl tangential inlet cross section of FIG. [Figure 1c2] FIG. 1b is a three-dimensional view of the BB gas positive swirl tangential inlet cross section of FIG. 1a. [Figure 1d1] FIG. 1b is a two-dimensional view of the CC gas reverse swirl tangential inlet cross section of FIG. [Figure 1d2]FIG. 1b is a three-dimensional view of the CC gas reverse swirl tangential inlet cross section of FIG. [Figure 1e1] FIG. 1b is a two-dimensional view of the cross section DD of FIG. [Figure 1e2] FIG. 1b is a three-dimensional view of the cross section DD of FIG. [Figure 1f1] FIG. 1b is a two-dimensional view of the E-E cross section of FIG. [Figure 1f2] FIG. 1b is a three-dimensional view of the E-E cross section of FIG. [Diagram 2] FIG. 2 is an assembly schematic diagram of the gas-liquid pintle injector of the present application from a second perspective. [Diagram 3] FIG. 1 is a cross-sectional schematic view of a first view of the gas-liquid pintle injector of the present application. [Figure 4] FIG. 2 is a cross-sectional schematic view of the gas-liquid pintle injector of the present application from a second perspective. [Diagram 5] FIG. 2 is a schematic diagram of injection holes having a rectangular opening shape arranged in a circumferential array of the pintle rod of the present application. [Figure 6] FIG. 2 is a schematic diagram of an ultra-small injection hole in the end face of the pintle rod of the present application. [Figure 7a] FIG. 2 is a diagram showing the atomization effect of a unidirectional swirling flow according to the prior art; [Figure 7b] FIG. 2 is a diagram showing the atomization effect of the "forward" and "reverse" swirling flows of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] (Design principle of the present invention) 1. Difficulties in the design of the present invention: The first difficulty is that the length of the gas-liquid pintle injector is limited and cannot be infinitely long, and when the gas flow path is not long enough, the swirling flow cannot advance sufficiently in the inner flow path, which causes spatially uneven atomization distribution in the circumferential direction after colliding with the radial liquid jet. The second difficulty is that the swirling flow assists atomization and faces the problem of rapid atomization after the atomization is uniform, so the combustion area approaches the outlet of the pintle rod 1, causing pintle rod burnout.

[0019] 2. To solve the first difficulty, that the two swirling flow directions are opposite. The liquid in the pintle rod is ejected from the pintle head nozzle with a rectangular opening in the radial direction, and the gas is ejected from the pintle head nozzle with an axial direction. After the gas and liquid collide, a spray cone with a certain angle (0-90 degrees) is formed. When no swirling flow is added, the gas density is much smaller than the liquid, so the gas injection speed is much larger than the liquid, which causes the momentum ratio (defined as the momentum ratio between the radial direction and the axial direction) to be too small, and the spray shape at the pintle head becomes very flat and elongated (the spray cone angle is close to 90 degrees). When a unidirectional swirling flow is added, the axial momentum of the gas is reduced, and the spray shape becomes a reasonable spray cone type (about 45-60 degrees). Gas swirl injection promotes atomization, but the swirl causes the spray to be spatially non-uniform in the circumferential direction. This is mainly because the length of the gas-liquid pintle injector cannot be infinitely long. If the gas flow path is not long enough, the swirl cannot advance sufficiently in the inner flow path, and after colliding with the radial liquid jet, a spatially non-uniform atomization distribution is caused in the circumferential direction. In a statistical sense, the time average of the spatial distribution of the spray is constant, but if a deviation occurs at a certain moment due to the transient characteristics of the spray, combustion oscillation occurs. Similar to the conventional technology, a reverse swirl is added to form a swirl structure with layers in the radial direction, and the inside of the swirl contacts the liquid jet to assist atomization, but the outside of the swirl acts in the opposite direction, causing the entire spray to be distributed spatially uniformly. Compared with the unidirectional swirling flow of the prior art "gas / liquid pintle injector with swirling flow to assist atomization and adjustable swirl degree", the prior art inner sleeve 2 delivers non-swirling gas and the outer sleeve 3 delivers swirling gas, the outer sleeve is long and the inner sleeve is short, and the swirling gas of the outer sleeve merges with the non-swirling gas of the inner sleeve at the outlet of the inner sleeve, forming a unidirectional swirling gas after merging, and is also sprayed out from the outlet end of the outer sleeve.The first improvement of the present application is that both the inner sleeve 2 and the outer sleeve 3 deliver swirling gas, and the swirling flow directions of the two swirling gases are opposite and both enter tangentially, that is, both produce swirling flow, but in opposite directions, where the swirling flow directions are opposite because the cutout directions of the inner sleeve 2 and the outer sleeve 3 are opposite. The second improvement of the present application is that the outlet ends of the two sleeves, the inner sleeve and the outer sleeve, are on the same plane and the heights of the outlet ends are equal, in this way, the inner swirling flow of the gas phase swirling flow is used to assist in atomization and change the spray swirl angle, but there is a possibility that the spray will be uneven, that is, it may oscillate at a certain time period, and since the outlet ends of the outer sleeve and the inner sleeve are on the same plane, when the inner swirling flow oscillates in the current plane, the outer swirling flow will provide a swirling flow in the opposite direction in the same plane, the outer swirling flow will swirl in the opposite direction, and the inner swirling flow will swirl forward, where the inner swirling flow functions to assist in atomization, and the outer swirling flow functions to control the swirling flow to be distributed as spatially uniformly as possible, which has the advantage.

[0020] 3. To solve the second difficulty, the design of the pintle head with small injection holes. The axial swirling flow of gas is injected, and the swirling flow functions to assist atomization, so the axial division distance of the liquid jet is small, and atomization is accelerated, that is, the atomization area and the combustion area are closer to the pintle rod head, and ablation occurs on the pintle rod. Therefore, the second improvement of the present application is to open a very small liquid injection hole at the bottom of the pintle. The first is the design principle of opening a small hole. The purpose of opening a very small hole at the pintle head is to eject kerosene from here. Originally, kerosene was ejected from the injection hole 7, which has a rectangular opening shape of the pintle rod inner passage 10, and was used to ensure the main atomization area. Currently, the kerosene is ejected from a very small hole, which can play a role similar to liquid film cooling, and the atomized liquid droplets evaporate and absorb heat, providing a protective role for the pintle head. Second, the design of the number and diameter of the small holes is based on the fact that the number of holes is too small and the diameter is too small, resulting in insufficient kerosene evaporation, neither of which can achieve the heat absorption and temperature reduction effect; the number of holes is too large and the diameter is too large, which affects the kerosene flow rate; the quantitative analysis of the number and diameter of the small holes depends on different operating conditions, and depends on how much flow rate absorbs how much heat and how much temperature needs to be reduced. In any case, the number and diameter of the small holes are based on the fact that they do not consume and affect the mass flow rate of the liquid propellant A excessively, while at the same time achieving the heat absorption effect of the droplets to protect the pintle from ablation.

[0021] Based on the above-mentioned principle of the invention, the present invention designs a gas-liquid pintle injector, which uses forward and reverse swirling flows to strengthen spray combustion and cool the head of the pintle rod of the gas-liquid pintle injector. As shown in Figures 1, 1a, 1b1, 1b2, 1c1, 1c2, 1d1, 1d2, 1e1, 1e2, 1f1, 1f2, 2, 3, 4, 5, 6, 7a and 7b, the gas-liquid pintle injector is used in rocket propulsion equipment, and is provided with a pintle rod 1, an inner sleeve 2 and an outer sleeve 3 which are coaxially arranged around the outer periphery of the pintle rod 1, and are sequentially arranged. The pintle rod 1 is used to provide a non-swirling flow of liquid, and the inner sleeve 2 and the outer sleeve 3 are used to provide a swirling flow of gas.

[0022] Two radial multi-layer swirling flow structures with opposite swirling flow directions are arranged in the inner sleeve 2 and the outer sleeve 3, thereby forming a gas-phase swirling flow with inner and outer layers, the inner side of the gas-phase swirling flow collides with the radial liquid jet at the head of the pintle rod 1 to intensify the spray, and the outer side of the gas-phase swirling flow reduces the circumferential non-uniformity of the atomization of the spray. Ultra-small injection holes 11 are opened on the end surface of the head of the pintle rod 1, and the pintle is protected from ablation by the evaporation heat absorption effect of the droplets formed by spraying and atomizing from the ultra-small injection holes 11. The radial liquid jet at the head of the pintle rod 1 is sprayed from injection holes 7 with rectangular opening shapes arranged in a circumferential array at the head of the pintle rod 1.

[0023] Furthermore, a pintle rod inner passage 10 is opened in the center of the pintle rod 1, an inner sleeve inner passage 8 is opened between the pintle rod 1 and the inner sleeve 2, and an outer sleeve inner passage 9 is provided between the inner sleeve 2 and the outer sleeve 3, the outlet ends of the inner sleeve inner passage 8 and the outer sleeve inner passage 9 are at the same height, and the outlet end of the pintle rod inner passage 10 protrudes a set distance outside the outlet ends of the inner sleeve inner passage 8 and the outer sleeve inner passage 9.

[0024] (Supplementary explanation 1) 1) An axial inner pintle rod passage 10 is opened in the center of the pintle rod 1, and is connected to a liquid propellant A supply system. The bottom of the passage 10 is a substantially hemispherical closed section, and a radially circumferential array of injection holes 7 having a rectangular opening shape is opened in the passage 10. 2) In addition to the rectangular injection hole 7, the end face of the pintle head is penetrated by a series of ultra-small injection holes 11, and the spray area that provides a small penetration distance and a large spray cone angle is distributed near the pintle head. 3) Two coaxial sleeves with lower end openings on the same plane are connected to the outer periphery of the pintle rod, namely, the inner sleeve 2 and the outer sleeve 3, and the lengths of the two sleeves are both shorter than the length of the pintle rod 1. Here, the inner sleeve 2 and the outer sleeve 3 are both connected to the gas forward swirl tangential inlet 5 and the gas reverse swirl tangential inlet 6, and are respectively connected to the gas propellant B supply system through these two tangential inlets, providing two gas swirl flows with opposite swirl directions; 4) The swirling flow of the inner sleeve and the outer sleeve forms a layered gas phase swirling flow, the inner side of the swirling flow gas collides with the radial liquid jet to strengthen the spray, and the outer side of the swirling flow gas reduces the circumferential non-uniformity of the atomization of the spray; Furthermore, the outlet end of the pintle rod inner passage 10 protrudes a set distance outside the outlet ends of the inner sleeve inner passage 8 and the outer sleeve inner passage 9, and this set distance is equal to the outer diameter of the pintle rod 1, preferably 12 mm, but is not limited to this.

[0025] The gas-liquid pintle injector further includes three parts, which are a pintle rod 1, an inner sleeve, and an outer sleeve, in the axial direction, in that order from top to bottom. The pintle rod 1 is provided with a liquid radial inlet 4 and a radial inlet liquid collection chamber 4-1 for providing a non-swirling flow of liquid, and the radial inlet liquid collection chamber 4-1 is connected to a pintle rod inner flow passage 10. The inner sleeve 2 is provided with a gas positive swirling tangential inlet 5 and a positive swirling tangential inlet air collection chamber 5-1 for providing a swirling flow of gas, and the positive swirling tangential inlet air collection chamber 5-1 is connected to the radial multi-port inlet 1. The pintle rod 1 and the inner sleeve 2 are connected to an inner sleeve inner flow path 8 on the inside of the radial multi-layer swirling flow structure, and the outer sleeve 3 is provided with a gas reverse swirling tangential inlet 6 and a reverse swirling tangential inlet air collection chamber 6-1 for providing a swirling flow of gas, and the reverse swirling tangential inlet air collection chamber 6-1 is connected to an outer sleeve inner flow path 9 on the outside of the radial multi-layer swirling flow structure, and the pintle rod 1 and the inner sleeve 2, and the inner sleeve 2 and the outer sleeve 3 are connected by flanges, respectively, and the forward rotation means rotating in a clockwise direction when viewed in a plane, and the reverse rotation means rotating in a counterclockwise direction when viewed in a plane.

[0026] Furthermore, the gas phase swirling flow structure, which is divided into inner and outer layers with opposite swirling flow directions, comprises a pintle rod 1, an inner sleeve 2, an outer sleeve 3, a gas positive swirling tangential inlet 5 and a positive swirling tangential inlet collection chamber 5-1 opened in the inner sleeve 2, a gas reverse swirling tangential inlet 6 and a reverse swirling tangential inlet collection chamber 6-1 opened in the outer sleeve 3, an inner sleeve inner flow path 8 between the pintle rod 1 and the inner sleeve 2, and an outer sleeve inner flow path 9 between the inner sleeve 2 and the outer sleeve 3, and the gas positive swirling tangential inlet 5 and the gas reverse swirling tangential inlet 6 have tangential inlets that are parallel to each other and have opposite directions.

[0027] (Supplementary explanation 2) The gas positive swirl tangential inlet 5 and the gas reverse swirl tangential inlet 6 may be arranged 180 degrees symmetrically with each other, or may be arranged at another angle with each other. The circumferential positions of the pintle rod 1, the inner sleeve 2, and the outer sleeve 3 are not limited.

[0028] Furthermore, the length of the pintle rod inner passage 10 is preferably, but not limited to, 80 to 100 mm, the length of the inner sleeve inner passage 8 is preferably, but not limited to, 65 to 75 mm, and the length of the outer sleeve inner passage 9 is preferably, but not limited to, 50 to 60 mm.

[0029] Furthermore, the gas-liquid pintle injector injects with a two-component propellant, which is divided into a liquid propellant A and a gas propellant B. The pintle rod inner passage 10 is connected to the supply system of the liquid propellant A via the liquid radial inlet 4, and the inner sleeve inner passage 8 and the outer sleeve inner passage 9 are connected to the gas propellant B via the gas forward swirl tangential inlet 5 and the gas reverse swirl tangential inlet 6, respectively.

[0030] Furthermore, the jet speed of the outlet airflow of the inner sleeve inner passage 8 is preferably, but not limited to, 150 to 250 m / s, the jet speed of the outlet airflow of the outer sleeve inner passage 9 is preferably, but not limited to, 150 to 250 m / s, and the liquid jet speed of the jet hole having a rectangular opening shape at the outlet of the pintle rod inner passage 10 is preferably, but not limited to, 20 to 40 m / s.

[0031] (Supplementary explanation 3) The injection velocity of the propellant in the inner sleeve 2 and the outer sleeve 3 is much greater than that in the central passage of the pintle rod 1. When the degree of swirl is sufficiently large, the circumferential shear action of the gas-phase swirl promotes the breakup of the radial jet at the head of the pintle rod 1, and the breakup distance of the axial liquid jet is reduced.

[0032] Furthermore, ultra-small injection holes 11 are opened in the end surface of the head of the pintle rod 1, and the ultra-small injection holes 11 are uniformly distributed in the circumferential direction of each set radius, and the number of small holes distributed in the circumferential direction of each radius is equal.

[0033] Furthermore, the number and diameter of the ultra-small injection holes 11 on the end surface of the head of the pintle rod 1 are determined based on the criteria of not excessively consuming or affecting the mass flow rate of the liquid propellant A, while at the same time fulfilling the evaporation heat absorption function of the droplets to protect the pintle from ablation. The diameter of the ultra-small injection holes 11 on the end surface of the head of the pintle rod 1 is preferably 0.06 to 0.1 mm, but is not limited thereto.

[0034] (Supplementary explanation 4) 7a and 7b are diagrams comparing the effects of a unidirectional swirl spray of the prior art and a bidirectional swirl spray of the present invention, respectively. In the prior art, a liquid jet is ejected from an injection hole having a rectangular opening shape, and is deflected under the action of a unidirectional gas swirl flow to produce a primary spray; the gas swirl flow in the pipe does not advance sufficiently, and the gas velocity becomes non-uniform in the circumferential direction of the annular gap outlet; as a result, after the gas collides with the radial jet at the pintle head, the spray shape may exhibit non-axisymmetric and non-uniform spatial distribution, which has an adverse effect on spray combustion in the combustion chamber; in the present invention, a liquid jet is ejected from an injection hole having a rectangular opening shape, and is deflected under the action of an inner gas swirl flow to produce a primary spray; and at the same time, is deflected in the opposite direction under the action of an outer gas swirl flow to produce a secondary spray, which further promotes atomization and reduces the non-uniformity of the spray in the circumferential direction; and further, the evaporation and heat absorption action of the atomized droplets formed by the injection from the ultra-small injection hole protects the pintle from abrasion.

[0035] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations to the present invention fall within the scope of the claims of the present invention and its equivalents, the present invention is intended to include these modifications and variations. [Explanation of symbols]

[0036] 1, pintle rod, 2, inner sleeve, 3, outer sleeve, 4, liquid radial inlet, 4-1, radial inlet liquid collection chamber, 5, gas positive swirl tangential inlet, 5-1, positive swirl tangential inlet collection chamber, 6, gas reverse swirl tangential inlet, 6-1, reverse swirl tangential inlet collection chamber, 7, injection hole with rectangular opening shape, 8, flow passage inside inner sleeve, 9, flow passage inside outer sleeve, 10, flow passage inside pintle rod, 11, ultra-small diameter injection hole.

Claims

1. A gas-liquid pintle injector, which is used in a rocket propulsion system, includes a pintle rod (1), an inner sleeve (2) and an outer sleeve (3) which are coaxially arranged around the outer periphery of the pintle rod (1) and are arranged in sequence, the pintle rod (1) being used to provide a non-swirling axial flow of liquid, and the inner sleeve (2) and the outer sleeve (3) being used to provide a swirling axial flow of gas. In the gas-liquid pintle injector, the forward and reverse swirling flows are used to strengthen spray combustion and cool the head of the pintle rod of the gas-liquid pintle injector, Two radial multi-layer swirling flows with opposite swirling directions are arranged inside the inner sleeve (2) and the outer sleeve (3), thereby forming a gas-phase swirling flow structure with inner and outer layers with opposite swirling directions. The inner side of the gas-phase swirling flow collides with the radial liquid jet at the head of the pintle rod (1), thereby strengthening the spray, and the outer side of the gas-phase swirling flow can reduce the circumferential non-uniformity of the atomization of the spray. The ultra-small diameter injection hole (11) is provided on the end surface of the head of the pintle rod (1). a pintle rod (1) that is provided with a nozzle hole (11) having an ultra-small diameter, and the pintle rod (1) is protected from ablation by the evaporation heat absorption action of atomized droplets formed by spraying from the ultra-small diameter nozzle hole (11), and a radial liquid jet from the head of the pintle rod (1) is sprayed from nozzle holes (7) having rectangular opening shapes that are arranged in a circumferential array on the head of the pintle rod (1).

2. 2. The gas-liquid pintle injector for cooling the head of the pintle rod of the gas-liquid pintle injector by enhancing spray combustion with forward and reverse swirling flows as claimed in claim 1, characterized in that: a pintle rod inner passage (10) is opened at the center of the pintle rod (1); an annular axial inner sleeve inner passage (8) is provided between the pintle rod (1) and the inner sleeve (2); an annular axial outer sleeve inner passage (9) is provided between the inner sleeve (2) and the outer sleeve (3); outlet ends of the inner sleeve inner passage (8) and the outer sleeve inner passage (9) are at the same height; and the outlet end of the pintle rod inner passage (10) protrudes a set distance outside the outlet ends of the inner sleeve inner passage (8) and the outer sleeve inner passage (9).

3. The gas-liquid pintle injector for enhancing spray combustion by positive and negative swirling flows and cooling the head of the pintle rod of the gas-liquid pintle injector as described in claim 2, characterized in that the set distance is equal to the outer diameter of the pintle rod (1), preferably 12 mm, but not limited to this.

4. The gas-liquid pintle injector includes three parts, which are arranged in the axial direction from top to bottom, namely, a pintle rod (1), an inner sleeve (2), and an outer sleeve (3). The pintle rod (1) is provided with a liquid radial inlet (4) and a radial inlet liquid collection chamber (4-1) for providing a non-swirling flow of liquid, and the radial inlet liquid collection chamber (4-1) is connected to a pintle rod inner flow path (10). The inner sleeve (2) is provided with a gas positive swirling tangential inlet (5) and a positive swirling tangential inlet air collection chamber (5-1) for providing a swirling flow of gas, and the positive swirling tangential inlet air collection chamber (5-1) is connected to the inner sleeve inner flow path (8). The outer sleeve (3) is provided with a gas positive swirling tangential inlet (5) and a positive swirling tangential inlet air collection chamber (5-1) for providing a swirling flow of gas, and the positive swirling tangential inlet air collection chamber (5-1) is connected to the inner sleeve inner flow path (8).

3. The gas-liquid pintle injector for cooling the head of the pintle rod of the gas-liquid pintle injector by enhancing spray combustion with forward and reverse swirling flows as claimed in claim 2, characterized in that a gas reverse swirling tangential inlet (6) and a reverse swirling tangential inlet air collection chamber (6-1) for providing a swirling flow of gas are provided, the reverse swirling tangential inlet air collection chamber (6-1) is connected to the outer sleeve inner flow path (9), the pintle rod (1) and the inner sleeve (2) are connected by flanges, and the inner sleeve (2) and the outer sleeve (3) are connected by flanges, respectively, and the forward swirl is a clockwise rotation in a plan view, and the reverse swirl is a counterclockwise rotation in a plan view.

5. 5. The gas-phase swirling flow structure having inner and outer layers with opposite swirling flow directions is formed by the pintle rod (1), the inner sleeve (2), the outer sleeve (3), the gas positive swirl tangential inlet (5) and the positive swirl tangential inlet collection chamber (5-1) opened in the inner sleeve (2), the gas reverse swirl tangential inlet (6) and the reverse swirl tangential inlet collection chamber (6-1) opened in the outer sleeve (3), the inner sleeve inner flow passage (8) between the pintle rod (1) and the inner sleeve (2), and the outer sleeve inner flow passage (9) between the inner sleeve (2) and the outer sleeve (3), and the gas positive swirl tangential inlet (5) and the gas reverse swirl tangential inlet (6) have tangential inlets parallel to each other and opposite directions.

6. 3. A gas-liquid pintle injector for cooling the head of a pintle rod of the gas-liquid pintle injector by enhancing spray combustion using positive and negative swirling flows as described in claim 2, characterized in that the length of the pintle rod inner passage (10) is preferably, but not limited to, 80 to 100 mm, the length of the inner sleeve inner passage (8) is preferably, but not limited to, 65 to 75 mm, and the length of the outer sleeve inner passage (9) is preferably, but not limited to, 50 to 60 mm.

7. 5. The gas-liquid pintle injector for cooling the head of the pintle rod of the gas-liquid pintle injector by enhancing spray combustion with forward and reverse swirling flows as claimed in claim 4, characterized in that the gas-liquid pintle injector injects with a two-component propellant, and the two-component propellant is divided into a liquid propellant A and a gas propellant B, the pintle rod inner passage (10) is connected to a supply system of the liquid propellant A through the liquid radial inlet (4), and the inner sleeve inner passage (8) and the outer sleeve inner passage (9) are respectively connected to the gas propellant B through a gas forward swirling tangential inlet (5) and a gas reverse swirling tangential inlet (6).

8. 3. A gas-liquid pintle injector for cooling the head of a pintle rod of a gas-liquid pintle injector by enhancing spray combustion with forward and reverse swirling flows as set forth in claim 2, characterized in that the jet speed of the outlet airflow of the inner sleeve inner flow passage (8) is preferably, but not limited to, 150 to 250 m / s, the jet speed of the outlet airflow of the outer sleeve inner flow passage (9) is preferably, but not limited to, 150 to 250 m / s, and the liquid jet speed at the outlet of the injection hole having a rectangular opening shape of the pintle rod inner flow passage (10) is preferably, but not limited to, 20 to 40 m / s.

9. 2. A gas-liquid pintle injector for cooling the head of a pintle rod of a gas-liquid pintle injector by enhancing spray combustion with forward and reverse swirling flows as claimed in claim 1, characterized in that ultra-small injection holes (11) are opened on the end surface of the head of the pintle rod (1), and these ultra-small injection holes (11) are uniformly distributed in different circumferential directions at each set radius, and the numbers of ultra-small injection holes uniformly distributed in different circumferential directions at each set radius are equal to each other.

10. The number and diameter of the ultra-small injection holes (11) opened on the end surface of the head of the pintle rod (1) are set based on the criteria that the mass flow rate of the liquid propellant A is consumed and affected as little as possible, while protecting the pintle from ablation by the evaporation heat absorption action of the droplets, and the diameter of the ultra-small injection holes (11) on the end surface of the head of the pintle rod (1) is preferably 0.06 to 0.1 mm, but is not limited thereto.

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