Swirl annular gap nozzle for gas generator fuel injection

Abstract

The present invention provides a swirl annular gap nozzle for fuel injection in a gas generator, comprising a nozzle outer ring and a nozzle core, the nozzle core being threadedly connected to the nozzle outer ring. During operation, the injectate passes through the nozzle core channel into the cavity formed by the nozzle core and the nozzle outer ring, generating a tangential force. The injectate is then injected into the gas generator combustion chamber through the annular gap formed by the nozzle core and the nozzle outer ring. The centrifugal annular gap nozzle generates centrifugal force during injection of the injectate, while the annular gap also enhances the nozzle's atomization. Combined with these features, the centrifugal annular gap nozzle exhibits the excellent properties of increased injectate atomization and improved mixing efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of gas generators, in particular to a swirl annular gap nozzle for fuel injection of a gas generator. Background Art

[0002] Gas generators, as a broad category of engines, have a wide range of applications, including chemical laser combustion chambers, combustion wind tunnel heaters, and aircraft aerodynamic catapults. Consisting primarily of an injection panel, combustion chamber, and flow-restricting duct, gas generators are designed to quickly complete the oxidizer-fuel reaction and output high power. However, the initial temperature of the combustible mixture within the gas generator is low, and the oxidizer-fuel mixture ratio often deviates from the chemically correct equivalence ratio, resulting in poor mixing. This makes ignition and stable combustion challenging, necessitating the design of the fuel nozzle. The injection method, which generates a tangential force within the fuel nozzle and injects the fuel into the combustion chamber through an annular gap, effectively enhances fuel atomization, thereby improving the mixing efficiency of the oxidizer and fuel, facilitating ignition. Furthermore, higher mixing efficiency promotes efficient combustion, thereby increasing the gas generator's output power. This innovative swirl annular gap nozzle is a key feature. Summary of the Invention

[0003] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a swirl annular gap nozzle for fuel injection in a gas generator, which enhances the fuel atomization effect and improves the mixing efficiency of the fuel and the oxidant.

[0004] To achieve the above purpose, the technical solution of the present invention is as follows:

[0005] A swirl annular gap nozzle for fuel injection in a gas generator, comprising: a lower nozzle outer cavity surface 104, an upper nozzle outer ring, and a nozzle core installed inside the nozzle outer ring;

[0006] The nozzle outer ring is used to be installed on the injection panel. The inner surface of the nozzle outer ring is provided with a nozzle outer ring internal thread 101, and the outer surface is provided with a nozzle outer ring external thread 102 connected to the injection panel. The nozzle outer ring internal thread 101 cooperates with the nozzle core external thread 201.

[0007] Nozzle core: used for injecting material into the nozzle; it includes a nozzle inner cavity surface 205 at the bottom, and a nozzle core outer thread 201 is provided on the outer surface of the nozzle core above the nozzle inner cavity surface 205; a cylindrical fuel channel 202 is provided in the center of the nozzle core for introducing fuel into the nozzle; a plurality of fuel swirl holes 204 are provided on the nozzle core, and the fuel swirl holes are respectively connected to the fuel channel 202 and the fuel storage bin 3, and are used to transport fuel from the fuel channel 202 to the fuel storage bin 3; the fuel swirl holes 204 are multiple swirl channels, one side of the swirl channel coincides with a tangent line of the inner circle of the cross section of the fuel channel center hole, and the other side is parallel to the tangent line, and the multiple swirl channels rotate in the same direction and at the same angle on the circumference of the cross section of the fuel channel center hole; the fuel swirl holes generate a tangential force relative to the center axis of the nozzle by allowing the fuel to enter the fuel storage bin 3 tangentially;

[0008] Fuel storage bin 3: used for retaining injection material before injection; the fuel storage bin 3 is surrounded by the inclined surfaces of the nozzle outer cavity surface 104 and the nozzle inner cavity surface 205. The lower end of the inclined surface of the nozzle inner cavity surface 205 is connected to a vertical line segment, and the vertical line segment and the nozzle outer cavity surface 104 form an injection annular gap 4;

[0009] The injection annular gap 4 is used to reduce the thickness of the fuel and then inject it into the combustion chamber; the nozzle annular gap is annular and cylindrical, and its cross section is concentric with the cross section of the fuel delivery pipeline.

[0010] As a preferred embodiment, the fuel swirl hole 204 is composed of four swirl channels, and the four channels are rotated 90 degrees in sequence along the same direction on the circumference of the cross section of the central hole of the fuel channel.

[0011] As a preferred embodiment, four nozzle outer ring mounting grooves 103 are evenly distributed along the circumferential direction on the bottom of the nozzle outer ring external thread 102 on the nozzle outer ring.

[0012] As a preferred embodiment, a nozzle core positioning step 203 is provided at the bottom of the nozzle core external thread 201 for positioning the nozzle core and the nozzle outer ring during installation; the step position of the nozzle core positioning step 203 corresponds to the top position of the nozzle outer cavity surface 104 .

[0013] As a preferred embodiment, a cross mounting groove 206 is provided at the bottom of the nozzle inner cavity surface 205 .

[0014] As a preferred method, the inclination angle of the nozzle inner cavity surface 205 is α, and the dimension at the outlet of the nozzle inner cavity surface D1 = D0 + 2δ + 2L1tanα, where D1 is the outlet diameter of the nozzle inner cavity surface 205, D0 is the diameter of the fuel channel 202, δ is the thickness of the nozzle core, and L1 is the height of the fuel storage tank. D0 and δ are determined by the mounting hole of the injection panel and are known parameters.

[0015] As a preferred embodiment, the inclination angle α of the nozzle inner cavity surface is 15°-25°.

[0016] As a preferred method, the size D2 of the nozzle outer cavity outlet is determined by the fuel flow requirement of the gas generator. The fuel injection pressure difference ΔP0 in the combustion chamber, the diameter D1 at the outlet of the nozzle inner cavity surface 205, and the nozzle flow coefficient C d Jointly decide to satisfy the relationship:

[0017]

[0018] Among them C d is the flow coefficient, which is given by the test calibration results and its value is between 0.2-0.4, ρ0 is the fuel density, ΔP0, Given by the gas generator design requirements, it is known here.

[0019] As a preferred embodiment, the height L2 of the nozzle annular gap 4 is 3-5 times the nozzle annular gap width (D2-D1) / 2.

[0020] As a preferred embodiment, the area of ​​the nozzle swirl hole 204 is not less than the area of ​​the injection ring gap 4, so as to ensure that no flow restriction occurs at the nozzle swirl hole. D4 is the diameter of the fuel swirl hole; n is the number of fuel swirl holes.

[0021] Among them, the fuel channel introduces fuel into the nozzle core;

[0022] The fuel swirl hole introduces the fuel in the fuel channel into the fuel storage bin and generates a tangential force;

[0023] The fuel further swirls in the fuel storage tank and enters the injection annular gap;

[0024] The fuel is injected into the combustion chamber through the injection annulus and mixed with the oxidizer and burned.

[0025] The outer ring of the nozzle is provided with mounting threads, the outer threads of the outer ring of the nozzle are used to mount the nozzle to the injection panel, and the inner threads of the outer ring of the nozzle are used to mount the nozzle core to the outer ring of the nozzle.

[0026] The outer ring of the nozzle is provided with a mounting groove for applying force to the mounting tool when the nozzle is mounted on the injection panel.

[0027] The outer ring of the nozzle is provided with an outer cavity surface for cooperating with the inner cavity surface of the nozzle to form a fuel storage bin and an injection annular gap.

[0028] The nozzle core is provided with a positioning step for positioning the nozzle core and the nozzle outer ring when they are installed.

[0029] The fuel swirl hole in the nozzle core is used to inject the fuel in the fuel channel into the fuel storage bin and generate a tangential force.

[0030] The fuel storage bin is used for storing a small amount of fuel and further developing the fuel swirl.

[0031] The injection annular gap is used for injecting fuel from the fuel storage tank into the combustion chamber with a smaller liquid film thickness.

[0032] In addition to the above parameters, the remaining parameters are non-limiting parameters and have no special requirements. Based on the above parameters, the basic profile parameters of a swirl annular gap nozzle for fuel injection in a gas generator can be determined.

[0033] Compared with the prior art, the swirl annular gap nozzle for fuel injection in a gas generator provided by the present invention has the following beneficial effects:

[0034] 1. The design method of swirl nozzle is integrated with the design method of annular gap nozzle, which further enhances the atomization effect of the injection flow, which will be beneficial to the combustion organization;

[0035] 2. The nozzle installation and component combination are designed to facilitate nozzle installation and application in various types of gas generators;

[0036] 3. This type of nozzle is suitable for different types of liquid fuels, broadening the application scenarios for different fuel gas generators;

[0037] 4. A design method for a swirl annular gap nozzle for fuel injection in a gas generator was obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of the assembly of a swirl annular gap nozzle for fuel injection in a gas generator according to the present invention;

[0039] Figure 2 Schematic diagram of the outer ring of the swirl annular gap nozzle for fuel injection in the gas generator of the present invention;

[0040] Figure 3 This is a schematic diagram of the core of the swirl annular gap nozzle for fuel injection in the gas generator of the present invention;

[0041] Explanation of the accompanying numbers: 101 is the internal thread of the nozzle outer ring, 102 is the external thread of the nozzle outer ring, 103 is the mounting groove of the nozzle outer ring, 104 is the outer cavity surface of the nozzle, 201 is the external thread of the nozzle core, 202 is the fuel channel, 203 is the positioning step of the nozzle core, 204 is the fuel swirl hole, 205 is the inner cavity surface of the nozzle, 206 is the cross mounting groove, 3 is the fuel storage tank, and 4 is the injection ring seam. DETAILED DESCRIPTION

[0042] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0043] Example

[0044] like Figure 1 The embodiment discloses a swirl annular gap nozzle for fuel injection in a gas generator, comprising: a lower nozzle outer cavity surface 104, an upper nozzle outer ring, and a nozzle core installed inside the nozzle outer ring;

[0045] The nozzle outer ring is used to be installed on the injection panel. The inner surface of the nozzle outer ring is provided with a nozzle outer ring internal thread 101, and the outer surface is provided with a nozzle outer ring external thread 102 connected to the injection panel. The nozzle outer ring internal thread 101 cooperates with the nozzle core external thread 201.

[0046] Nozzle core: used for injecting material into the nozzle; it includes a nozzle inner cavity surface 205 at the bottom, and a nozzle core outer thread 201 is provided on the outer surface of the nozzle core above the nozzle inner cavity surface 205; a cylindrical fuel channel 202 is provided in the center of the nozzle core for introducing fuel into the nozzle; a plurality of fuel swirl holes 204 are provided on the nozzle core, and the fuel swirl holes are respectively connected to the fuel channel 202 and the fuel storage bin 3, and are used to transport fuel from the fuel channel 202 to the fuel storage bin 3; the fuel swirl holes 204 are multiple swirl channels, one side of the swirl channel coincides with a tangent line of the inner circle of the cross section of the fuel channel center hole, and the other side is parallel to the tangent line, and the multiple swirl channels rotate in the same direction and at the same angle on the circumference of the cross section of the fuel channel center hole; the fuel swirl holes generate a tangential force relative to the center axis of the nozzle by allowing the fuel to enter the fuel storage bin 3 tangentially;

[0047] Fuel storage bin 3: used for retaining injection material before injection; the fuel storage bin 3 is surrounded by the inclined surfaces of the nozzle outer cavity surface 104 and the nozzle inner cavity surface 205. The lower end of the inclined surface of the nozzle inner cavity surface 205 is connected to a vertical line segment, and the vertical line segment and the nozzle outer cavity surface 104 form an injection annular gap 4;

[0048] The injection annular gap 4 is used to reduce the thickness of the fuel and then inject it into the combustion chamber; the nozzle annular gap is annular and cylindrical, and its cross section is concentric with the cross section of the fuel delivery pipeline.

[0049] Preferably, Figure 3 The fuel swirl hole 204 is composed of four swirl channels, and the four channels are rotated 90 degrees in sequence along the same direction on the circumference of the cross section of the central hole of the fuel channel.

[0050] Four nozzle outer ring mounting grooves 103 are evenly distributed along the circumferential direction at the bottom of the nozzle outer ring external thread 102 on the nozzle outer ring.

[0051] A nozzle core positioning step 203 is provided at the bottom of the nozzle core external thread 201 for positioning the nozzle core and the nozzle outer ring when they are installed; the position of the nozzle core positioning step 203 corresponds to the top position of the nozzle outer cavity surface 104 .

[0052] A cross mounting groove 206 is provided at the bottom of the nozzle inner cavity surface 205 .

[0053] The inclination angle of the nozzle inner cavity surface 205 is α, and the dimension at the outlet of the nozzle inner cavity surface D1 = D0 + 2δ + 2L1tanα, where D1 is the outlet diameter of the nozzle inner cavity surface 205, D0 is the diameter of the fuel channel 202, δ is the thickness of the nozzle core, and L1 is the height of the fuel storage tank. D0 and δ are determined by the mounting hole of the injection panel and are known parameters.

[0054] The inclined surface angle α of the nozzle inner cavity surface is 15°-25°.

[0055] The nozzle cavity outlet size D2 is determined by the fuel flow requirement of the gas generator. The fuel injection pressure difference ΔP0 in the combustion chamber, the diameter D1 at the outlet of the nozzle inner cavity surface 205, and the nozzle flow coefficient C d Jointly decide to satisfy the relationship:

[0056]

[0057] Among them C d is the flow coefficient, which is given by the test calibration results and its value is between 0.2-0.4, ρ0 is the fuel density, ΔP0, Given by the gas generator design requirements, it is known here.

[0058] The height L2 of the nozzle annular gap 4 is 3-5 times the nozzle annular gap width (D2-D1) / 2.

[0059] The area of ​​the nozzle swirl hole 204 is not less than the area of ​​the injection ring gap 4, ensuring that no flow restriction occurs at the nozzle swirl hole, that is, D4 is the diameter of the fuel swirl hole; n is the number of fuel swirl holes.

[0060] Among them, the fuel channel introduces fuel into the nozzle core;

[0061] The fuel swirl hole introduces the fuel in the fuel channel into the fuel storage bin and generates a tangential force;

[0062] The fuel further swirls in the fuel storage tank and enters the injection annular gap;

[0063] The fuel is injected into the combustion chamber through the injection annulus and mixed with the oxidizer and burned.

[0064] The outer ring of the nozzle is provided with a mounting groove for applying force to the mounting tool when the nozzle is mounted on the injection panel.

[0065] The outer ring of the nozzle is provided with an outer cavity surface for cooperating with the inner cavity surface of the nozzle to form a fuel storage bin and an injection annular gap.

[0066] The fuel swirl hole in the nozzle core is used to inject the fuel in the fuel channel into the fuel storage bin and generate a tangential force.

[0067] The fuel storage bin is used for storing a small amount of fuel and further developing the fuel swirl.

[0068] The injection annular gap is used for injecting fuel from the fuel storage tank into the combustion chamber with a smaller liquid film thickness.

[0069] The outer ring of the nozzle is connected to the injection panel of the gas generator. The nozzle core has the function of introducing fuel and generating tangential force. The fuel storage tank 3 has the function of fuel storage and swirl development. The injection ring gap 4 injects the fuel into the combustion chamber. Figure 3 The fuel is supplied into the nozzle core through the fuel channel, and then into the fuel storage tank 3 composed of the nozzle core and the nozzle outer ring. The fuel generates a vortex in the storage tank 3 and further develops, and is injected into the gas generator combustion chamber through the injection annular gap 4 to organize combustion. The superimposed vortex in the annular gap enhances the fuel atomization effect, thereby improving the combustion efficiency.

[0070] Specifically, a sealing gasket is added between the nozzle outer ring thread 101 and the injection panel to ensure that the nozzle as a whole is sealed with the injection panel. The nozzle outer ring mounting groove 103 is used as a tool fulcrum when installing the nozzle outer ring 1.

[0071] Specifically, the fuel enters the nozzle core from the fuel passage 202 .

[0072] The specific nozzle core is connected to the nozzle outer ring through the nozzle outer ring internal thread 102 and the nozzle core external thread 201. The nozzle core positioning step 203 is used for positioning when the nozzle core and the nozzle outer ring are connected, and the cross mounting groove 206 is used for tool force during the above connection.

[0073] Specifically, after the fuel enters the nozzle core through the fuel channel 202 , it enters the fuel storage bin 3 formed by the inclined surface of the nozzle inner cavity surface 205 and the nozzle outer cavity surface through the circumferentially arranged fuel swirl holes 204 .

[0074] Specifically, the axis of a single nozzle of the fuel swirl hole 204 is parallel to the tangent line of the inner circle of the cross section of the fuel channel 202 . After the fuel flows out through the swirl hole 204 , it generates a tangential force and swirls into the fuel storage bin 3 .

[0075] Specifically, the swirling fuel entering the fuel storage tank 3 further develops and swirls into the combustion chamber through the injection annular gap 4 to organize combustion. The injection annular gap 4 is limited by size so that the particle size of the fuel injected into the combustion chamber is reduced, thereby achieving the effect of enhancing atomization. At the same time, the swirling effect increases the shear force between the fuel droplets, which is beneficial to enhancing the fuel atomization effect.

[0076] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A swirl annular gap nozzle for fuel injection in a gas generator, characterized in that: include: A lower nozzle outer cavity surface (104), an upper nozzle outer ring, and a nozzle core installed inside the nozzle outer ring; The nozzle outer ring is used to be installed on the injection panel. The inner surface of the nozzle outer ring is provided with a nozzle outer ring internal thread (101), and the outer surface is provided with a nozzle outer ring external thread (102) connected to the injection panel. The nozzle outer ring internal thread (101) cooperates with the nozzle core external thread (201). Nozzle core: used for injecting material into the nozzle; comprising a nozzle inner cavity surface (205) at the bottom, and a nozzle core outer thread (201) provided on the outer surface of the nozzle core above the nozzle inner cavity surface (205); a cylindrical fuel channel (202) is provided in the center of the nozzle core for introducing fuel into the nozzle; a plurality of fuel swirl holes (204) are provided on the nozzle core, and the fuel swirl holes are respectively connected to the fuel channel (202) and the fuel storage bin (3) for transporting fuel from the fuel channel (202) to the fuel storage bin (3); the fuel swirl holes (204) are a plurality of swirl channels, one side of the swirl channel coincides with a tangent line of the inner circle of the cross section of the central hole of the fuel channel, and the other side is parallel to the tangent line, and the plurality of swirl channels rotate in sequence in the same direction and at the same angle on the circumference of the cross section of the central hole of the fuel channel; the fuel swirl holes generate a tangential force relative to the central axis of the nozzle by allowing the fuel to enter the fuel storage bin (3) tangentially; A fuel storage bin (3) is used for the injection material to reside before injection; the fuel storage bin (3) is surrounded by the inclined surface of the nozzle outer cavity surface (104) and the nozzle inner cavity surface (205); the lower end of the inclined surface of the nozzle inner cavity surface (205) is connected to a vertical line segment, and the vertical line segment and the nozzle outer cavity surface (104) form an injection annular gap (4); The injection annular gap (4) is used to reduce the thickness of the fuel and then inject it into the combustion chamber; the injection annular gap is annular and cylindrical, and its cross section is concentric with the cross section of the fuel delivery pipe; The nozzle cavity outlet size D2 is determined by the fuel flow requirement of the gas generator. The fuel injection pressure difference ΔP0 in the combustion chamber, the diameter D1 at the outlet of the nozzle inner cavity surface (205), and the nozzle flow coefficient C d Jointly decide to satisfy the relationship: Among them C d is the flow coefficient, which is given by the test calibration results and its value is between 0.2-0.4, ρ0 is the fuel density, ΔP0, Given by the gas generator design requirements, it is known here.

2. A swirl annular gap nozzle for fuel injection in a gas generator according to claim 1, characterized in that: The fuel swirl hole (204) is composed of four swirl channels, and the four channels are rotated 90 degrees in sequence along the same direction on the circumference of the cross section of the central hole of the fuel channel.

3. The swirl annular gap nozzle for fuel injection in a gas generator according to claim 1, characterized in that: Four nozzle outer ring mounting grooves (103) are evenly distributed along the circumferential direction at the bottom of the nozzle outer ring external thread (102) on the nozzle outer ring.

4. A swirl annular gap nozzle for fuel injection in a gas generator according to claim 1, characterized in that: A nozzle core positioning step (203) is provided at the bottom of the nozzle core external thread (201) for positioning the nozzle core and the nozzle outer ring when they are installed; the step position of the nozzle core positioning step (203) corresponds to the top position of the nozzle outer cavity surface (104).

5. The swirl annular gap nozzle for fuel injection in a gas generator according to claim 1, characterized in that: A cross mounting groove (206) is provided at the bottom of the nozzle inner cavity surface (205).

6. The swirl annular gap nozzle for fuel injection in a gas generator according to claim 1, characterized in that: The inclination angle of the nozzle inner cavity surface (205) is α, and the dimension at the nozzle inner cavity surface outlet is D1=D0+2δ+2L1tanα, where D1 is the outlet diameter of the nozzle inner cavity surface (205), D0 is the diameter of the fuel channel (202), δ is the thickness of the nozzle core, and L1 is the height of the fuel storage tank. D0 and δ are determined by the injection panel mounting hole and are known parameters.

7. A swirl annular gap nozzle for fuel injection in a gas generator according to claim 6, characterized in that: The inclined surface angle α of the nozzle inner cavity surface is 15°-25°.

8. The swirl annular gap nozzle for fuel injection in a gas generator according to claim 6, characterized in that: The height L2 of the injection annular gap (4) is 3-5 times the nozzle annular gap width (D2-D1) / 2.

9. The swirl annular gap nozzle for fuel injection in a gas generator according to claim 1, characterized in that: The area of ​​the fuel swirl hole (204) is not less than the area of ​​the injection ring gap (4), ensuring that no flow restriction occurs at the nozzle swirl hole, that is, D4 is the diameter of the fuel swirl hole; n is the number of fuel swirl holes.

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