A flame stabilizer with directional controlled fuel injection

Abstract

The present invention discloses a flame stabilizer with directional controllable fuel injection, and the technical field of flame stabilizers, comprising a conical column section and a long straight section connected to each other; the cross section of the conical column section is triangular; the cross section of the long straight section is rectangular, a fuel lead pipe and a high-pressure air lead pipe are provided inside the long straight section, a fuel joint, a high-pressure air joint and a fuel injection port are provided outside the long straight section, and the fuel injection port is provided on two opposite sides of the long straight section; the fuel lead pipe is connected to the fuel joint and the fuel injection port; the high-pressure air lead pipe is provided in the fuel lead pipe, the outer pipe wall of the high-pressure air lead pipe is separated from the inner pipe wall of the fuel lead pipe, the air inlet of the high-pressure air lead pipe is connected to the high-pressure air lead pipe, the air outlet of the high-pressure air lead pipe is opposite to and separated from the fuel injection port to form a shear atomization cavity, and the air outlet of the high-pressure air lead pipe is in an outwardly expanding structure in the direction of the shear atomization cavity; thereby, many problems existing in the prior art are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of flame stabilizers, in particular to a flame stabilizer with directional control fuel injection. Background Art

[0002] To achieve a higher thrust-to-weight ratio, modern advanced turbofan engines require higher gas temperatures before the turbine and higher temperatures in the main combustion chamber. This increases gas flow and velocity, significantly increasing the temperature and velocity of the incoming fuel into the turbofan afterburner or ramjet / afterburner. While higher temperatures facilitate rapid fuel evaporation, they also shorten the effective penetration depth of the injected fuel, weakening its mixing capacity and carrying the risk of fuel nozzle coking.

[0003] While higher velocities facilitate shearing and fragmenting of the fuel and airflow to a certain extent, they also limit the fuel's ability to penetrate and its residence time within the combustion chamber, making combustion more difficult. Furthermore, since the stabilizer and fuel supply pipe operate for extended periods within the high-temperature combustion chamber, they require cooling and protection. Therefore, it is particularly important to integrate the stabilizer and fuel supply system, introducing an appropriate amount of cooling air to cool the fuel and stabilizer to improve their operational stability, reliability, and service life.

[0004] In summary, developing a solution that can simultaneously achieve stable combustion, improve the atomization, diffusion and mixing performance of the fuel, increase the injection depth of the fuel, increase the flame expansion angle, and shorten the circumferential cross-flame distance between stabilizers in the combustion chamber has become an urgent problem to be solved. Summary of the Invention

[0005] The purpose of the present invention is to provide a flame stabilizer with directional controlled fuel injection to achieve stable combustion, improve the atomization, diffusion and mixing performance of the fuel, increase the injection depth of the fuel, increase the flame expansion angle, and shorten the circumferential flame distance between stabilizers in the combustion chamber.

[0006] In order to solve the above technical problems, the present invention provides a flame stabilizer with directional controlled fuel injection, comprising a conical section and a long straight section connected to each other; the cross-section of the conical section is triangular; the cross-section of the long straight section is rectangular, a fuel lead pipe and a high-pressure air lead pipe are provided inside the long straight section, a fuel connector, a high-pressure air connector and a fuel injection port are provided outside the long straight section, and the fuel injection port is provided on two opposite sides of the long straight section; the fuel lead pipe is connected to the fuel connector and the fuel injection port; the high-pressure air lead pipe is provided in the fuel lead pipe, the outer tube wall of the high-pressure air lead pipe is separated from the inner tube wall of the fuel lead pipe, the air inlet of the high-pressure air lead pipe is connected to the high-pressure air lead pipe, and the air outlet of the high-pressure air lead pipe is opposite to and separated from the fuel injection port to form a shear atomization chamber, and the air outlet of the high-pressure air lead pipe is an outwardly expanding structure in the direction toward the shear atomization chamber.

[0007] In one embodiment, the outlet of the high-pressure air duct has an outward-expanding swing angle α of 10° to 20°.

[0008] In one embodiment, the diameter of the high-pressure air duct is r, the depth of the shear atomization chamber is d, and d=r / 2.

[0009] In one embodiment, the diameter of the high-pressure air duct r is 0.5 mm to 1.5 mm.

[0010] In one embodiment, the diameter of the fuel pipe is R=1.1mm-2.1mm.

[0011] In one embodiment, the fuel injection port is provided on a side of the long straight section adjacent to the tapered cylindrical section.

[0012] In one embodiment, a plurality of the fuel injection ports are provided on two opposite sides of the long straight section, and the plurality of the fuel injection ports are arranged in a straight line along the height direction of the long straight section.

[0013] In one embodiment, the tapered cylindrical section and the long straight section are integrally formed.

[0014] The beneficial effects of the present invention are as follows:

[0015] (1) Enhance fuel atomization and oil mist mixing.

[0016] The high-pressure air duct introduces high-pressure air, while the fuel duct introduces fuel. Because the outlet of the high-pressure air duct is opposite and separated from the fuel injection port, forming a shear atomization chamber, the outlet of the high-pressure air duct expands outward toward the shear atomization chamber. This effectively forms a skirt-shaped vortex generator (VG), coupling the high-pressure air and fuel to form an aerodynamically enhanced atomization spray pattern. The VG first forms a flow vortex within the shear atomization chamber. The aerodynamic disturbance and shearing effects of the vortex cause the fuel jet to break up. The strong oscillation of the uneven cavity at the outlet intensifies the shearing effect, further exacerbating the breakup of the oil mist droplets. Then, the high-speed incoming flow is injected orthogonally through the fuel injection port. The introduced high-pressure gas carries the fuel inside the fuel and undergoes high-intensity friction shear with the high-speed mainstream. The turbulence intensity is enhanced and the aerodynamic parameter gradient changes sharply. Accompanied by large shear deformation of the fuel and the fusion of oil and gas, the fuel is more easily broken into droplets and further forms fine oil mist, so as to achieve the purpose of enhancing atomization and oil-gas mixing.

[0017] (2) Enhance the penetration depth of fuel. Thanks to the introduction of high-pressure gas, on the one hand, it intersects with the high-speed mainstream to form a backflow to the local low-speed area, allowing the fuel to reach a farther circumferential position with a lower dynamic pressure. On the other hand, the fuel itself is accelerated to a certain extent by the viscosity, and the increase in the fuel momentum ratio improves the penetration ability of the fuel. Therefore, the high-pressure gas enhances the local mass transfer capacity, and the fuel between adjacent radial flame stabilizers can meet in a shorter distance, reflecting that the flame behind the flame stabilizer can be linked in a shorter distance, achieving the goal of shortening the distance of the linked flame. Increase the injection depth of the fuel and improve the diffusion and mixing performance of the fuel.

[0018] (3) Achieve local oxygenation and pressurization. The introduction of high-pressure gas through the high-pressure gas duct can improve the situation where the gas consumes a lot of oxygen after burning in the main combustion chamber. The increase in local pressure is conducive to improving the oil and gas follow-up performance, and effectively copes with the difficulty of fuel atomization under low pressure and low temperature conditions, achieving good distribution of oil mist and improving local combustion performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solution of the present invention, the following is a brief introduction to the drawings required for use in the implementation. Obviously, the drawings described below are only some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 It is a perspective structural diagram provided by an embodiment of the present invention;

[0021] Figure 2 yes Figure 1A schematic diagram of a partially enlarged top view of the structure;

[0022] Figure 3 Contour map of oil mist field concentration for the flame stabilizer with integrated design for non-directional fuel injection;

[0023] Figure 4 This is the oil mist field concentration contour map of the flame stabilizer with an integrated design of directional controlled fuel injection + low bleed air volume;

[0024] Figure 5 This is the oil mist field concentration contour map of the flame stabilizer with an integrated design of directional controlled fuel injection + high air intake.

[0025] The reference numerals are as follows:

[0026] 10. Cone column section;

[0027] 20. Long straight section; 21. Fuel injection port;

[0028] 30. Fuel pipe; 31. Fuel connector;

[0029] 40. High-pressure gas duct; 41. High-pressure gas connector; 42. Skirt-type vortex generator;

[0030] 50. Shear atomization chamber. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0032] The present invention provides a flame stabilizer with directional control fuel injection, which is implemented as follows Figure 1 and Figure 2 As shown, the fuel tank comprises a conical section 10 and a long straight section 20 connected to each other; the conical section 10 has a triangular cross-section; the long straight section 20 has a rectangular cross-section; a fuel pipe 30 and a high-pressure air pipe 40 are provided inside the long straight section 20; a fuel connector 31, a high-pressure air connector 41 and a fuel injection port 21 are provided outside the long straight section 20; the fuel pipe 30 is connected to the fuel connector 31 and the fuel injection port 21; the high-pressure air pipe 40 is provided inside the fuel pipe 30, the outer wall of the high-pressure air pipe 40 is separated from the inner wall of the fuel pipe 30, the air inlet of the high-pressure air pipe 40 is connected to the high-pressure air pipe 40, and the air outlet of the high-pressure air pipe 40 is opposite to and separated from the fuel injection port 21 to form a shear atomization chamber 50, and the air outlet of the high-pressure air pipe 40 is in an outwardly expanding structure in the direction toward the shear atomization chamber 50.

[0033] During operation, the fuel connector 31 is connected to the fuel input, thereby delivering the fuel to the fuel duct 30, while the high-pressure gas connector 41 is connected to the high-pressure gas input, thereby delivering the high-pressure gas to the high-pressure gas duct 40. The fuel and high-pressure gas are then transported together to the fuel injection port 21 and converged. Because the outlet of the high-pressure gas duct 40 is structured to expand outward toward the shear atomization chamber 50, the high-pressure gas duct 40 is equivalent to forming a skirt-shaped vortex generator 42. Therefore, the high-pressure gas and fuel are coupled to form an aerodynamically enhanced atomization spray mode. The skirt-shaped vortex generator 42 first forms a flow vortex in the shear atomization chamber 50. The aerodynamic disturbance and shearing action of the vortex cause the fuel jet to break up. Under the strong oscillation of the uneven outlet cavity, the disturbance shear effect is enhanced, further exacerbating the breakup of the oil mist droplets. Then, the high-speed incoming flow is orthogonally injected through the fuel injection port 21. The introduced high-pressure gas carries the fuel inside the fuel and undergoes high-intensity friction shearing with the high-speed mainstream. The turbulence intensity is enhanced and the aerodynamic parameter gradient changes sharply. Accompanied by large shear deformation of the fuel and the fusion of oil and gas, the fuel is more easily broken into droplets and further forms fine oil mist, so as to achieve the purpose of enhancing atomization and oil-gas mixing.

[0034] In addition, this embodiment also enhances the penetration depth of the fuel. Specifically, thanks to the introduction of high-pressure gas, on the one hand, it intersects with the high-speed mainstream to form a backflow to the local low-speed area, allowing the fuel to reach a farther circumferential position with a lower dynamic pressure. On the other hand, the fuel itself is accelerated to a certain extent by the viscosity, and the increase in the fuel momentum ratio improves the penetration ability of the fuel. Therefore, the high-pressure gas enhances the local mass transfer capacity, and the fuel between adjacent radial flame stabilizers can meet in a shorter distance, reflecting that the flame behind the flame stabilizer can be linked in a shorter distance, achieving the goal of shortening the distance of the linked flame. Increase the injection depth of the fuel and improve the diffusion and mixing performance of the fuel.

[0035] Furthermore, this embodiment also achieves localized oxygenation and pressurization. Specifically, the introduction of high-pressure gas through the high-pressure gas duct 40 can alleviate the situation where the gas burns in the main combustion chamber and consumes a large amount of oxygen. The increase in local pressure helps improve oil and gas tracking and effectively addresses the difficulty of fuel atomization under low-pressure and low-temperature conditions, achieving good distribution of oil mist and improving local combustion performance.

[0036] like Figure 2As shown, in this embodiment, the outlet of the high-pressure air duct 40 is preferably set to have an outwardly expanding swing angle α of 10° to 20°, such as 10°, 11°, 12°, 13°, 14°, 15°, 16°, 17°, 18°, 19° and 20°; and it is also preferred to set the diameter of the high-pressure air duct 40 to r, the depth of the shear atomization chamber 50 to d, and d=r / 2. At this time, the diameter of the high-pressure air duct 40 is r=0.5mm~1.5mm, such as 0. 5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm and 1.5mm, etc.; and at this time, the diameter of the fuel pipe 30 is R=1.1mm~2.1mm, such as 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm and 2.1mm, etc.

[0037] After adopting this setting method, the structural parameters of the flame stabilizer can be optimized to obtain better use effect.

[0038] like Figure 1 As shown, in this embodiment, the fuel injection port 21 is preferably arranged on a side of the long straight section 20 adjacent to the tapered cylindrical section 10 .

[0039] by Figure 1 The direction shown is for reference only. The long straight section 20 is connected to the conical column section 10 using its left side. Therefore, the fuel injection port 21 will be located on the left side of the long straight section 20 to ensure that the fuel injection port 21 can be arranged adjacent to the conical column section 10, thereby continuing to optimize the structure of the flame stabilizer to further improve the performance of flame stability.

[0040] like Figure 1 As shown, in this embodiment, a plurality of fuel injection ports 21 are preferably provided on both opposite sides of the long straight section 20 , and the plurality of fuel injection ports 21 are arranged in a straight line along the height direction of the long straight section 20 .

[0041] by Figure 1 The direction shown is for reference only. At this time, the fuel injection ports 21 are arranged on the outward and inward surfaces of the long straight section 20, and the fuel injection ports 21 on the long straight section 20 are arranged in a top-down manner, so that the multiple fuel injection ports 21 can cover a wider range, thereby further optimizing the use effect of the flame stabilizer.

[0042] like Figure 1 As shown, in this embodiment, the tapered column section 10 and the long straight section 20 are preferably formed in one piece.

[0043] After adopting this arrangement, the connection strength between the conical column section 10 and the long straight section 20 can be strengthened, thereby improving the working stability and service life of the flame stabilizer.

[0044] The flame stabilizer of the above embodiment is applied in the integrated design of the super combustion chamber. Under the conditions of high temperature and high flow rate, it ensures stable combustion, enhances the penetration depth of fuel, accelerates the circumferential propagation of the flame, strengthens the mixing of oil mist, and improves the combustion effect.

[0045] To verify the performance of the flame stabilizer described above, it was assumed that the diameter R of the fuel duct 30 was 1.6 mm, the diameter r of the high-pressure air duct 40 was 1 mm, the outward-expanding angle α of the high-pressure air duct 40 was 14°, and the depth d of the shear atomization cavity 50 was r / 2. Numerical simulations were performed using a square tube binary model with a flame stabilizer having the same fuel injection area but without a directional fuel injection mechanism.

[0046] 2. Comparison of oil mist field between fuel injection structure models with and without directional control

[0047] like Figure 3 and Figure 4 As shown in FIG. 1 , the oil mist field concentration contour diagrams of the two models are taken at the section where the fuel injection port 21 on the side of the flame stabilizer is located. Figure 3 This is the calculation result of the oil mist field without the directional control fuel injection structure model. Figure 4 The calculation results of the oil mist field with the directional control fuel injection structure model are shown below. Figure 3 As shown in the figure, the oil mist penetration depth is narrow, the circumferential expansion ability is weak, and the downstream oil mist follows the main flow to shrink and distribute behind the stabilizer. Figure 4 In the oil mist field concentration contour diagram, it can be seen that the flame stabilizer with a directional controlled fuel injection structure has improved circumferential penetration capability. Compared with the flame stabilizer without a directional controlled fuel injection structure, the penetration depth is increased from 0.17 times the slot width to 0.36 times the slot width. The density of the contour lines must reflect the degree of atomization of the oil droplets. The oil mist field concentration with a directional controlled fuel injection structure is sparse, which is manifested as a more even fuel distribution and improved atomization. The difference between the two models lies in whether a directional controlled fuel injection structure is set on the stabilizer long straight section 20. The injection position, fuel injection flow rate and temperature are the same during the numerical simulation calculation. This shows that the flame stabilizer with a directional controlled fuel injection structure can increase the fuel penetration depth and improve the atomization, diffusion and mixing performance of the fuel.

[0048] 3. Comparison of oil mist field under different air induction rates for the fuel injection structure model with directional control

[0049] like Figure 4 and Figure 5The figure shows the oil mist concentration contour map of the directional fuel injection structure model with high-pressure airflow of 0.001kg / s and 0.004kg / s, respectively. The cross section is the cross section of the fuel injection port 21 on the side of the flame stabilizer. In comparison, the fuel penetration depth of the strong air flow model can reach 0.64 times the slot width, which is a significant improvement compared to the weak air flow model of 0.36 times the slot width. At the same time, the oil mist distribution is more uniform. This shows that a higher air flow intensity can enhance the fuel momentum ratio, provide a deeper circumferential penetration depth, and provide favorable conditions for flame cross-linking between the stabilizer circumference under more stringent incoming flow conditions. In addition, the diffusion and mixing performance of the fuel are improved, which helps to organize combustion.

[0050] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A flame stabilizer with directional controlled fuel injection, characterized in that: It includes interconnected tapered column segments and long straight segments; The cross section of the cone-column section is triangular; The cross section of the long straight section is rectangular, a fuel duct and a high-pressure gas duct are provided inside the long straight section, a fuel connector, a high-pressure gas connector and a fuel injection port are provided outside the long straight section, and the fuel injection port is provided on two opposite sides of the long straight section; The fuel pipe is connected to the fuel joint and the fuel injection port; The high-pressure air duct is arranged in the fuel duct, the outer wall of the high-pressure air duct is separated from the inner wall of the fuel duct, and the air inlet of the high-pressure air duct is connected to the high-pressure air duct. The air outlet of the high-pressure air duct is opposite to and separated from the fuel injection port to form a shear atomization cavity. In the direction toward the shear atomization cavity, the air outlet of the high-pressure air duct is in an outwardly expanding structure.

2. The flame stabilizer according to claim 1, characterized in that The air outlet of the high-pressure air duct is expanded outward at an outward swing angle α of 10° to 20°.

3. The flame stabilizer according to claim 1, characterized in that The diameter of the high-pressure air duct is r, the depth of the shear atomization chamber is d, and d=r / 2.

4. The flame stabilizer according to claim 3, characterized in that The diameter of the high-pressure air duct is r=0.5mm-1.5mm.

5. The flame stabilizer according to claim 3, characterized in that The diameter of the fuel pipe is R=1.1mm-2.1mm.

6. The flame stabilizer according to claim 1, characterized in that The fuel injection port is arranged on a side of the long straight section adjacent to the tapered column section.

7. The flame stabilizer according to claim 1, characterized in that A plurality of fuel injection ports are provided on both opposite sides of the long straight section, and the plurality of fuel injection ports are arranged in a straight line along the height direction of the long straight section.

8. The flame stabilizer according to claim 1, characterized in that The tapered column section and the long straight section are integrally formed.

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