An oxygen-enriched gas atomizing nozzle

Abstract

This invention discloses an oxygen-enriched fuel gas atomizing nozzle, relating to the field of wide-range active cooling engine propellant injection. It includes a fuel inlet, a gas-liquid mixing chamber, a fuel inlet, a fuel manifold, a mixing chamber inlet, a nozzle, and a sonic flow meter. Downstream of the fuel inlet is a ring-shaped fuel manifold coaxial with the gas-liquid mixing chamber, which communicates with the gas-liquid mixing chamber through the mixing chamber inlet. The axial length and cross-sectional area of ​​the gas-liquid mixing chamber should ensure a fuel residence time of less than 10 ms. The total area of ​​the mixing chamber inlet should ensure that the momentum ratio of the fuel passing through the mixing chamber inlet to the momentum of the fuel gas within the gas-liquid mixing chamber is less than 0.1. For a wide-range active cooling injector with a fixed cross-sectional area nozzle, during engine start-up, the oxygen-enriched fuel gas atomizing nozzle can atomize the fuel, which is still in a low-temperature liquid state, thereby ensuring fuel atomization and mixing quality, and improving ignition performance and combustion efficiency.

Description

Technical Field

[0001] This invention relates to the field of wide-area active cooling engine propellant injection, and more particularly to an oxygen-enriched fuel gas atomizing nozzle. Background Technology

[0002] Wide-range active cooling engines require injectors to achieve high-quality fuel atomization and mixing across a wide operating range to ensure stable and efficient combustion. However, after active cooling, the fuel temperature rises sharply, and its physical state changes from liquid to supercritical (or gaseous), resulting in a significant decrease in density. A fixed cross-sectional area nozzle cannot meet the atomization requirements of this wide range of fuel phase changes. For example, nozzles for high-temperature supercritical fuel injection typically have a large cross-sectional area, which cannot simultaneously guarantee the atomization quality of the low-temperature liquid fuel during startup, especially under low-flow conditions.

[0003] High-temperature oxygen-enriched fuel gas (such as hydrogen peroxide catalytic decomposition gas) is characterized by high activity and strong reactivity. Using oxygen-enriched fuel gas to atomize fuel can not only improve the atomization quality of liquid fuel and the fuel / gas mixture level, but also significantly improve ignition performance and engine combustion efficiency.

[0004] However, existing technologies have the drawback that wide-area injectors with fixed nozzle cross-sectional areas cannot simultaneously achieve the injection atomization performance of both cryogenic liquid fuels and supercritical fuels, which greatly limits their performance. Summary of the Invention

[0005] The technical problem this invention aims to solve is to overcome the shortcomings of existing technologies and propose an oxygen-enriched fuel gas atomizing nozzle. Addressing the limitation that wide-area injectors with fixed nozzle cross-sectional areas cannot simultaneously achieve atomization performance for both cryogenic liquid fuels and supercritical fuels, this invention utilizes an oxygen-enriched fuel gas atomizing nozzle to atomize fuel still in a cryogenic liquid state during engine startup. This ensures fuel atomization and mixing quality and effectively improves ignition performance.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An oxygen-enriched gas atomizing nozzle includes a gas-liquid mixing chamber (2) and gas inlets (1) and nozzles (6) disposed at both ends of the gas-liquid mixing chamber (2), and an oxygen-enriched gas generator (10) disposed outside the gas-liquid mixing chamber (2). The gas inlets (1), the gas-liquid mixing chamber (2), and the nozzles (5) are arranged sequentially from left to right along the axis and are connected. A fuel manifold (4) in an annular shape is disposed circumferentially on the outer side of the gas-liquid mixing chamber (2), and the fuel manifold (4) is coaxially distributed with the gas-liquid mixing chamber (2). A plurality of mixing chamber inlet holes (5) are evenly distributed circumferentially on the outer wall of the gas-liquid mixing chamber (2), and the gas... The material manifold (4) is connected to the gas-liquid mixing chamber (2) through the mixing chamber inlet hole (5), and the axial length and cross-sectional area of ​​the gas-liquid mixing chamber (2) are set so that the gas residence time in the gas-liquid mixing chamber (2) is less than 10ms; the oxygen-enriched gas generator (10) is connected to the sonic flow meter (7) through the first gas pipeline (8), and the sonic flow meter (7) is connected to the gas inlet (1) through the second gas pipeline (9); the fuel manifold (4) is provided with a fuel inlet (3) at the lower end, and the fuel inlet (3) is connected to the external fuel supply system (11) through the fuel supply pipeline (12).

[0008] Preferably, the gas-liquid mixing chamber (2) controls the gas residence time to less than 10 ms according to the following formula:

[0009]

[0010] In the formula: τ r L is the gas residence time. m A is the axial length of the gas-liquid mixing chamber (2); m Let be the cross-sectional area of ​​the gas-liquid mixing chamber (2); ρ is the oxygen-enriched gas flow rate; G The density of oxygen-rich gas;

[0011] Preferably, the total area A of the mixing chamber inlet hole (5) is designed to be... p The momentum φ of the fuel passing through the inlet hole (5) of the mixing chamber. F The momentum φ of the gas in the gas-liquid mixing chamber (2) is less than that of the gas. G .

[0012] Preferably, the throat diameter of the sonic flow meter (7) is smaller than the diameter of the gas inlet (1), the gas-liquid mixing chamber (1), the nozzle (6), the first gas pipeline (8), the second gas pipeline (9), and the oxygen-enriched gas generator (10).

[0013] Preferably, the momentum φ of the fuel through the inlet hole (5) of the mixing chamber F The momentum φ of the gas in the gas-liquid mixing chamber (2) G The ratio φF / φ G Less than 0.1.

[0014] Preferably, the liquid inlet hole (5) of the mixing chamber can be a straight hole, an oblique hole or a tangential hole, and the number of liquid inlets is at least 4. The cross-sectional shape of the liquid inlet hole is at least one of the following: circular, elliptical, rectangular, rhomboid or raindrop-shaped.

[0015] Preferably, the materials of the gas inlet (1), gas-liquid mixing chamber (2), fuel inlet (3), fuel manifold (4), mixing chamber liquid inlet (5), nozzle (6), sonic flow meter (7), first gas pipeline (8), second gas pipeline (9), and oxygen-enriched gas generator (10) are all high-temperature alloy steel that is resistant to high temperatures and compatible with oxygen-enriched gas.

[0016] Preferably, the gas inlet (1), gas-liquid mixing chamber (2), fuel inlet (3), fuel manifold (4), mixing chamber liquid inlet (5), and nozzle (6) are obtained by at least one of machining, welding, or additive manufacturing integrated forming.

[0017] Compared with the prior art, the present invention provides an oxygen-enriched gas atomizing nozzle, which has the following beneficial effects:

[0018] During the start-up phase of a wide-range active cooling engine, the fuel is still in a low-temperature liquid state. At this time, the oxygen-enriched gas atomizing nozzle can atomize the fuel through structures such as the gas inlet, fuel manifold, mixing chamber liquid inlet, nozzle, oxygen-enriched gas generator, and fuel supply system, ensuring fuel atomization quality and gas mixing level, while improving ignition performance and combustion efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the geometric parameters of the atomizing nozzle of the present invention.

[0021] In the diagram: 1. Gas inlet; 2. Gas-liquid mixing chamber; 3. Fuel inlet; 4. Fuel manifold; 5. Liquid inlet to mixing chamber; 6. Nozzle; 7. Sonic flow meter; 8. First gas pipeline; 9. Second gas pipeline; 10. Oxygen-enriched gas generator; 11. Fuel supply system; 12. Fuel supply pipeline. Detailed Implementation

[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0023] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0024] Example:

[0025] Reference Figure 1-2 An oxygen-enriched gas atomizing nozzle, the main structure of which includes a gas inlet 1, a gas-liquid mixing chamber 2, a fuel inlet 3, a fuel manifold 4, a liquid inlet 5 for the mixing chamber, a nozzle 6, and a sonic flow meter 7. The gas inlet 1 is the gas inlet of the oxygen-enriched gas atomizing nozzle; the fuel inlet 3 is the fuel inlet of the oxygen-enriched gas atomizing nozzle; and the nozzle 6 is the gas-liquid spray hole of the oxygen-enriched gas atomizing nozzle.

[0026] Among them, the gas inlet 1, the gas-liquid mixing chamber 2 and the nozzle 6 are distributed and connected along the axis from upstream to downstream, forming a flow path of oxygen-rich gas in the gas atomizing nozzle; the downstream of the fuel inlet 3 is connected to the fuel manifold 4; the fuel manifold 4 is an annular chamber located outside the gas-liquid mixing chamber 2 and coaxially distributed with it;

[0027] The mixing chamber inlet holes 5 are evenly distributed circumferentially on the wall of the gas-liquid mixing chamber 2. The fuel manifold 4 is connected to the gas-liquid mixing chamber 2 through the mixing chamber inlet holes 5. Therefore, the flow velocity of fuel decreases after entering the fuel manifold 4, thereby ensuring that the fuel can enter the gas-liquid mixing chamber evenly circumferentially through the mixing chamber inlet holes 5. The mixing chamber inlet holes 5 can be straight holes perpendicular to the wall of the gas-liquid mixing chamber 2, oblique holes at a certain angle to the wall of the gas-liquid mixing chamber 2, or tangential holes tangential to the wall of the gas-liquid mixing chamber 2. To ensure that the mixing chamber inlet holes 5 are evenly distributed circumferentially on the wall of the gas-liquid mixing chamber 4, the number of inlet holes is at least 4. The cross-sectional shape of the mixing chamber inlet holes 5 can be circular, elliptical, rectangular, rhomboid, teardrop-shaped, etc.

[0028] Since oxygen-enriched gas is typically a high-temperature gas with high activity and reactivity, it is necessary to prevent chemical reactions between the oxygen-enriched gas and the fuel within the gas-liquid mixing chamber 2. Furthermore, if the fuel is hydrocarbon, carbon buildup must be prevented to avoid changes in the physical state of the hydrocarbon fuel due to thorough mixing at thermal equilibrium, which could lead to a high pressure ratio. Therefore, the residence time τ of the high-temperature oxygen-enriched gas through the gas-liquid mixing chamber 2 is crucial. r It should be less than 10ms. See appendix. Figure 2 Let the axial length L of the gas-liquid mixing chamber 2 be... m and cross-sectional area A m Then there is

[0029]

[0030] in, ρ is the flow rate of the oxygen-enriched fuel gas flowing through the gas-liquid mixing chamber 2. G The density of the oxygen-rich gas.

[0031] To ensure uniform fuel atomization, the fuel entering the gas-liquid mixing chamber 2 through the liquid inlet 5 should form a uniform circumferential liquid film on the inner wall of the gas-liquid mixing chamber 2. This requires that the momentum of the fuel passing through the liquid inlet 5 must be less than the momentum of the combustion gas inside the gas-liquid mixing chamber 2. Taking the case of a direct injection hole where the liquid inlet 5 is perpendicular to the wall of the gas-liquid mixing chamber 2 as an example, let A be the total area of ​​the liquid inlet 5. p The momentum of the fuel passing through the inlet hole 5 of the mixing chamber is...

[0032]

[0033] The momentum of the combustion gas in the gas-liquid mixing chamber 2 is

[0034]

[0035] Typically, when φ F / φ G When the concentration is less than 0.1, it exhibits good atomization effect.

[0036] The oxygen-enriched gas used for atomization is generated by an oxygen-enriched gas generator 10, and connected to the first gas pipeline 8, the sonic flow meter 7, and the second gas pipeline 9, which is connected to the gas inlet 1, supplying a certain amount of oxygen-enriched gas to the atomizing nozzle; the flow rate of the oxygen-enriched gas is determined by the total outlet temperature T of the oxygen-enriched gas generator 10. c Total pressure P c The throat diameter d of the sonic flowmeter 7 t The determination is based on the physical expression described in equation (4); where, To measure the oxygen-enriched gas flow rate passing through the sonic flow meter 7, R G γ is the gas constant of oxygen-enriched combustion gas. G δ is the specific heat ratio of oxygen-enriched fuel gas. t The throat area of ​​the sonic flowmeter 7 is calculated as shown in equation (5):

[0037]

[0038]

[0039] Therefore, the throat diameter of the sonic flow meter 7 should be smaller than the diameter of the gas inlet 1, the gas-liquid mixing chamber 2, the nozzle 6, the first gas pipeline 8, the second gas pipeline 9, and the oxygen-enriched gas generator 10.

[0040] Fuel is supplied to the oxygen-enriched gas atomizing nozzle via the fuel supply system 11, fuel supply line 12, and fuel inlet 3. Before entering the oxygen-enriched gas atomizing nozzle, the fuel can first be cooled in the active cooling engine combustion chamber before atomization and injection. The active cooling portion is not described in detail in this solution, and related information is omitted from the accompanying drawings.

[0041] Since oxygen-enriched gas is usually at high temperatures and has strong oxidizing properties, the materials of the oxygen-enriched gas atomizing nozzle assembly and the pipelines connected to it (including gas inlet 1, gas-liquid mixing chamber 2, fuel inlet 3, fuel manifold 4, mixing chamber liquid inlet 5, nozzle 6, sonic flow meter 7, first gas pipeline 8, second gas pipeline 9, and oxygen-enriched gas generator 10) should all be high-temperature alloy steel that is resistant to high temperatures and compatible with oxygen-enriched gas.

[0042] Based on the appendix Figure 1 The structural characteristics of the oxygen-enriched gas atomizing nozzle given in the paper are as follows: the gas inlet 1, gas-liquid mixing chamber 2, fuel inlet 3, fuel manifold 4, mixing chamber liquid inlet 5, and nozzle 6 can be processed by traditional machining methods such as mechanical processing and welding, or by additive manufacturing integrated molding.

[0043] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An oxygen-enriched gas atomizing nozzle, comprising a gas-liquid mixing chamber (2) and gas inlets (1) and nozzles (6) disposed at both ends of the gas-liquid mixing chamber (2), and an oxygen-enriched gas generator (10) disposed outside the gas-liquid mixing chamber (2), characterized in that: The gas inlet (1), gas-liquid mixing chamber (2) and nozzle (6) are distributed and connected along the axis from left to right. A fuel manifold (4) in the shape of an annular chamber is arranged around the gas-liquid mixing chamber (2), and the fuel manifold (4) is coaxially distributed with the gas-liquid mixing chamber (2). The gas-liquid mixing chamber (2) has multiple mixing chamber inlet holes (5) evenly distributed circumferentially on its outer wall. The fuel manifold (4) is connected to the gas-liquid mixing chamber (2) through the mixing chamber inlet holes (5). The axial length and cross-sectional area of ​​the gas-liquid mixing chamber (2) are set so that the gas residence time in the gas-liquid mixing chamber (2) is less than 10ms. The total area of ​​the mixing chamber inlet holes (5) is designed to be such that... The momentum of the fuel passing through the inlet hole (5) of the mixing chamber. The momentum of the gas in the gas-liquid mixing chamber (2) is less than that of the gas. ; The oxygen-enriched gas generator (10) is connected to a sonic flow meter (7) through a first gas pipeline (8), and the sonic flow meter (7) is connected to a gas inlet (1) through a second gas pipeline (9). The fuel manifold (4) is provided with a fuel inlet (3) at its lower end. The fuel inlet (3) is connected to the external fuel supply system (11) through the fuel supply pipeline (12).

2. The oxygen-enriched fuel gas atomizing nozzle according to claim 1, characterized in that, The gas-liquid mixing chamber (2) controls the gas residence time to less than 10 ms according to the following formula: ； In the formula: This refers to the gas residence time. The axial length of the gas-liquid mixing chamber (2) is given. Let be the cross-sectional area of ​​the gas-liquid mixing chamber (2); This refers to the flow rate of oxygen-enriched gas. The density of oxygen-rich gas.

3. The oxygen-enriched fuel gas atomizing nozzle according to claim 1, characterized in that, The throat diameter of the sonic flow meter (7) is smaller than the diameter of the gas inlet (1), the gas-liquid mixing chamber (2), the nozzle (6), the first gas pipeline (8), the second gas pipeline (9), and the oxygen-enriched gas generator (10).

4. The oxygen-enriched gas atomizing nozzle according to claim 1, characterized in that, The momentum of fuel through the inlet port (5) of the mixing chamber The momentum of the gas in the gas-liquid mixing chamber (2) ratio Less than 0.

1.

5. The oxygen-enriched fuel gas atomizing nozzle according to claim 1, characterized in that, The liquid inlet hole (5) of the mixing chamber is a straight hole, an oblique hole or a tangential hole, and the number of liquid inlet holes is at least 4. The cross-sectional shape of the liquid inlet hole is at least one of the following: circular, elliptical, rectangular, rhomboid or raindrop-shaped.

6. The oxygen-enriched fuel gas atomizing nozzle according to claim 1, characterized in that, The materials of the gas inlet (1), gas-liquid mixing chamber (2), fuel inlet (3), fuel manifold (4), mixing chamber inlet (5), nozzle (6), sonic flow meter (7), first gas pipeline (8), second gas pipeline (9), and oxygen-enriched gas generator (10) are all high-temperature alloy steel that is resistant to high temperatures and compatible with oxygen-enriched gas.

7. The oxygen-enriched fuel gas atomizing nozzle according to claim 1, characterized in that, The gas inlet (1), gas-liquid mixing chamber (2), fuel inlet (3), fuel manifold (4), mixing chamber liquid inlet (5), and nozzle (6) are obtained by at least one of machining or additive manufacturing integrated forming.

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