Self-spinning combustion chamber quincunx-shaped wall surface internal spiral evaporation pipe

Abstract

The invention discloses a self-spinning combustion chamber quincunx wall surface inner spiral evaporation pipe, relates to the technical field of micro aero-engine combustion chambers, and solves the problems that an existing evaporation pipe is complex in structure, difficult to manufacture, large in flow loss and low in combustion efficiency due to non-uniform mixing of fuel oil and air. The device comprises an oil spraying pipe, a plurality of support plate blades and an evaporation pipe, the oil spraying pipe is arranged at an inlet section of the evaporation pipe, the support plate blades are uniformly arranged around the oil spraying pipe, and the other ends of the support plate blades are connected with the inner wall of the evaporation pipe; the radial section of the inner wall of the evaporation pipe is plum blossom-shaped and rotates along the guide line. The special shape of the quincunx-shaped wall face is utilized, the contact area of fuel oil and surrounding hot air is increased, fluid is guided to spin through rotation of the supporting plate blades and the quincunx-shaped wall face in the flowing direction, the mixing effect of the fuel oil and air is enhanced, the fuel oil is evaporated more evenly, fluid distribution is improved, turbulent flow is enhanced, and the occupied space of a combustion chamber is reduced; the combustion efficiency of the combustor is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of micro-aeroengine combustors, and specifically to a plum-blossom-shaped wall inner spiral evaporation tube with a spin flow in the combustor. Background Art

[0002] Micro-aeroengines are complex and precise thermal machines, which have the advantages of small volume, light weight, fast response, high thrust-to-weight ratio, etc., and are thus widely used in military and civilian fields. Micro-aeroengines can not only be used as the power source for flight devices such as unmanned aerial vehicles and cruise missiles, but also can be used as small portable generators to provide power for ground devices. However, due to the volume limitation of micro-aeroengines, the characteristic size of their combustors is smaller than that of conventional-scale combustors, resulting in an extremely short mixing and combustion time of air and fuel, which easily causes problems such as incomplete fuel combustion and poor combustion stability, and further leads to a reduction in engine efficiency or even flameout. Therefore, the combustor has become an important part in the design of micro-aeroengines.

[0003] Annular combustors with evaporation tubes are widely used in micro-aeroengines because of their advantages such as small occupied volume, light structural weight, and fast fuel evaporation rate. As a key component of the combustor, the evaporation tube plays a role in multiple aspects such as combustion efficiency, temperature control, structural stability, and lightweight. Reasonable design of the evaporation tube can not only improve the working efficiency of the combustor and achieve high-performance combustion of fuel, but also significantly enhance the overall performance and reliability of the engine, which is of great significance for the development and application of micro-aeroengines. At present, the commonly used simple straight-tube type and "L"-type structures for evaporation tubes cannot effectively mix fuel and air sufficiently. Therefore, some combustors adopt spiral evaporation tubes or microchannel evaporation tubes in the design to achieve efficient heat exchange. However, the former has high manufacturing complexity, and the spiral structure occupies more space and is not suitable for micro-engines with limited space; the latter also has the problem of high manufacturing difficulty, and impurities or small particles may block the narrow channels, affecting fluid flow and reducing performance. Summary of the Invention

[0004] In order to solve the problems of the existing evaporation tube structure being complex and difficult to manufacture, large flow losses, and uneven mixing of fuel and air resulting in low combustion efficiency mentioned above, the present invention hereby provides a plum-blossom-shaped wall inner spiral evaporation tube with a spin flow in the combustor. The present invention utilizes the special shape of the plum-blossom-shaped wall to increase the contact area between fuel and the surrounding hot gas. At the same time, through the support plate blades at the pipe inlet and the rotation of the plum-blossom-shaped wall along the flow direction to guide the fluid to spin, the problem of insufficient mixing of fuel and air is solved, enabling the fuel to evaporate more evenly, improving the fluid distribution and enhancing turbulence. While reducing the occupied space of the combustor, the combustion efficiency of the combustor is improved, which is of great significance for enhancing the performance of micro-aeroengines.

[0005] The present invention provides a plum blossom-shaped inner spiral evaporation tube with a spin current in the combustion chamber, which specifically includes an oil injection pipe, a plurality of support plate blades, and an evaporation tube. The oil injection pipe is arranged at the inlet section of the evaporation tube, and a plurality of support plate blades are evenly arranged around the oil injection pipe. The other ends of the support plate blades are connected to the inner wall of the evaporation tube; the radial cross-section of the inner wall of the evaporation tube is plum blossom-shaped and rotates along the guiding line.

[0006] Furthermore, the number of petals of the plum blossom shape is 5.

[0007] Furthermore, the plum blossom shape at the inner wall of the evaporation tube at the outlet position rotates clockwise by an angle of 1.5 petal units along the flow direction compared to the plum blossom shape at the inner wall at the inlet position.

[0008] Furthermore, the distance from the center of the arc of the petal part of the plum blossom shape to the axis of the evaporation tube is half of the outer radius of the evaporation tube.

[0009] Furthermore, the outer radius of the evaporation tube is 9 mm to 10 mm; the radius of the arc of the petal part of the plum blossom shape is 3 mm to 4 mm.

[0010] Furthermore, the petals of the plum blossom shape are smoothly connected by fillets, and the radius of the fillet is 2 mm to 3 mm.

[0011] Furthermore, the evaporation tube further includes a transition section and an evaporation section. The inlet section, the transition section, and the evaporation section are connected in sequence. The inlet section and the evaporation section are straight pipes, and the transition section is a bent pipe.

[0012] Furthermore, the installation angle of the support plate blades is 10 degrees to 30 degrees.

[0013] Furthermore, the thickness of the support plate blades is 0.5 mm to 1 mm, and the chord length of the blades is 8 mm to 10 mm.

[0014] Furthermore, the inner diameter of the oil injection pipe is 2 mm to 4 mm, and the outer diameter is 5 mm to 6 mm.

[0015] The beneficial effects of the plum blossom-shaped inner spiral evaporation tube with a spin current in the combustion chamber of the present invention are as follows:

[0016] (1) A spiral evaporation tube within a plum blossom-shaped wall of a combustion chamber for spin flow according to the present invention guides the fluid to spin through the provided support plate blades and the plum blossom-shaped wall rotating along the guiding line. The introduction of the spin flow effectively enhances the turbulent effect within the evaporation tube, enabling the fluid to come into contact with the tube wall more fully during the flow process, thereby improving the heat transfer efficiency. The rotational movement of the fluid not only increases the mixing of heat within the fluid but also reduces the formation of the boundary layer through high-frequency perturbations, promoting the uniform distribution of heat within the evaporation tube. The plum blossom-shaped wall enhances the flow area of the fluid, avoiding dead zones and inefficient regions within the pipeline, thus improving the heat exchange efficiency.

[0017] (2) A spiral evaporation tube within a plum blossom-shaped wall of a combustion chamber for spin flow according to the present invention, the structure of the plum blossom-shaped wall helps to more effectively guide the air flow, increasing the contact time between the air flow and the atomized fuel and its contact area with the wall surface. This not only promotes the full mixing of air and fuel but also promotes the evaporation and gasification of liquid fuel. The spin flow causes strong rotation and perturbation during the fuel flow process, enhancing the uniformity of fuel atomization. Through more uniform atomization, the evaporation efficiency of the fuel is greatly improved, further enhancing the combustion efficiency.

[0018] (3) A spiral evaporation tube within a plum blossom-shaped wall of a combustion chamber for spin flow according to the present invention, the plum blossom-shaped wall structure enhances the thermal exchange stability of the entire system by optimizing the fluid path, reducing phenomena such as knocking, jitter, or incomplete combustion caused by uneven fuel distribution. The rotating jet of the spin flow can form a stable rotating flow field within the combustion region, which can not only promote the full combustion of the fuel but also avoid flame instability caused by excessive air flow perturbation.

[0019] (4) A spiral evaporation tube within a plum blossom-shaped wall of a combustion chamber for spin flow according to the present invention, micro-aero engines have strict requirements for volume and weight. By adopting the combined design of spin flow and plum blossom-shaped wall, more efficient heat exchange can be achieved within a limited space, thereby reducing the surface area and volume requirements of the evaporator and cooling system. In addition, the improved heat exchange efficiency means that lighter materials and more compact structural designs can be used, thereby reducing the weight of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings forming a part of this application are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0021] In the drawings:

[0022] Figure 1 is a three-dimensional structural schematic diagram of a spiral evaporation tube within a plum blossom-shaped wall of a combustion chamber for spin flow according to the present invention;

[0023] Figure 2 It is a side view of the spiral evaporation tube inside the plum blossom-shaped wall of the combustion chamber of a spin current according to the present invention;

[0024] Figure 3 It is a schematic diagram of the inlet structure of the spiral evaporation tube inside the plum blossom-shaped wall of the combustion chamber of a spin current according to the present invention;

[0025] Figure 4 It is a schematic diagram of the outlet structure of the spiral evaporation tube inside the plum blossom-shaped wall of the combustion chamber of a spin current according to the present invention;

[0026] Wherein: 1 - fuel injection pipe, 2 - support plate blade, 3 - evaporation tube, 4 - schematic guiding line 1, 5 - schematic guiding line 2, 6 - inlet section length, 7 - transition section radius, 8 - evaporation section length, 9 - outer wall diameter of the evaporation tube, 10 - inner wall diameter of the fuel injection pipe, 11 - outer wall diameter of the fuel injection pipe, 12 - petal arc radius, 13 - transition fillet radius between petals. Specific embodiments

[0027] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0029] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0030] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0031] Specific Embodiment 1: Refer to Figures 1 - 4 Specifically describe this embodiment. A plum blossom-shaped wall inner spiral evaporation tube of a spin flow combustion chamber described in this embodiment specifically includes an oil injection pipe 1, five support plate blades 2, and an evaporation tube 3. The oil injection pipe 1 is arranged at the inlet section of the evaporation tube 3. The inner diameter 10 of the inner wall of the oil injection pipe 1 is 2 mm to 4 mm, the outer diameter 11 of the outer wall of the oil injection pipe 1 is 5 mm to 6 mm, and the length of the oil injection pipe 1 is 12 mm to 16 mm.

[0032] Five support plate blades 2 are evenly arranged around the oil injection pipe 1. The other end of the support plate blade 2 is connected to the inner wall of the evaporation tube 3. The support plate blade 2 is a straight blade, which plays a role in fixing the oil injection pipe and can effectively guide the air flow, enhancing the generation of the spin flow and the atomization effect of the fuel. The installation angle of the support plate blade 2 is 10 degrees to 30 degrees. The thickness of the support plate blade 2 is 0.5 mm to 1 mm, and the chord length of the blade is 8 mm to 10 mm.

[0033] The radial cross-section of the inner wall of the evaporation tube 3 is in the shape of a plum blossom; from the inlet end to the outlet end of the evaporation tube 3, the plum blossom-shaped cross-sections at different positions on the inner wall of the evaporation tube 3 rotate clockwise along the guiding line. The guiding line includes a schematic guiding line 1 4 and a schematic guiding line 2 5, as Figure 1 shown.

[0034] The number of petals of the plum blossom shape is 5. The plum blossom shape on the inner wall at the outlet position of the evaporation tube 3 rotates clockwise by an angle of 1.5 petal units compared to the plum blossom shape on the inner wall at the inlet position along the flow direction, so that the cross-section of the inner wall of the entire pipe at different positions presents a plum blossom-shaped inner wall surface with different rotation angles from the inlet, thus forming a plum blossom-shaped inner spiral structure to further guide the spin of the air flow.

[0035] The distance from the center of the arc of the petal part of the plum blossom shape to the axis of the evaporation tube 3 is half of the outer radius of the evaporation tube 3. The outer radius of the evaporation tube 3 is 9 mm to 10 mm; the radius 12 of the arc of the plum blossom-shaped petal is 3 mm to 4 mm. The petals of the plum blossom shape are smoothly connected by fillets, and the radius 13 of the transition fillet between the petals is 2 mm to 3 mm.

[0036] The evaporation tube 3 also includes a transition section and an evaporation section. The inlet section, the transition section, and the evaporation section are connected in sequence. The inlet section and the evaporation section are straight pipes, and the transition section is a bent pipe. The inlet section length 6 of the inlet section is 14 to 18 mm, and the oil injection pipe 1 is fixed by the support plate blade 2; the transition section is a bent pipe, and the radius of the arc formed by the axis of the transition section, that is, the transition section radius 7, is 60 to 65 mm; the evaporation section is a straight pipe, and the evaporation section length 8 is 75 to 80 mm.

[0037] The specific working principle and process of the plum blossom-shaped wall inner spiral evaporation tube of the combustion chamber for spin current in the present invention are as follows:

[0038] According to Figure 1 shown, the external air flow first passes through the inlet section of the evaporation tube 3, enters the transition section through the support plate blades 2 at the inlet. During this process, the air flow is deflected by the guiding action of the support plate blades 2, thereby reducing the axial velocity and generating radial and tangential velocities. As Figure 1 and 3 shown, the deflection direction of the support plate blades 2 is the same as the rotation direction of the plum blossom-shaped wall, so as to improve the turbulence intensity and rotation intensity of the air flow as much as possible. At the same time, the fuel is sprayed into the transition section of the evaporation tube 3 through the fuel injection pipe 1 and mixed with the air flow flowing through the support plate blades 2. The air flow with higher turbulence also enables it to be fully mixed with the fuel, avoiding problems such as detonation, jitter or incomplete combustion caused by uneven fuel distribution.

[0039] Then, the fuel and air enter the transition section with a plum blossom-shaped inner wall together. The combination of the elbow pipe and the plum blossom-shaped inner spiral structure in the transition section can strengthen the continuous rotation of the air flow and further increase the turbulence. After entering the evaporation section, the swirl degree of the air flow further increases and the axial velocity decreases, thereby increasing the heat exchange time between the air flow and the fuel in the evaporation tube, enabling the fuel to be further mixed with the air and fully evaporated and atomized. In addition, the swirl of the fluid not only increases the mixing of heat inside the fluid, but also reduces the formation of the boundary layer through high-frequency perturbation, increases the convective heat transfer coefficient, strengthens the heat transfer between the air flow and the wall surface, and improves the evaporation and atomization efficiency of the liquid fuel.

[0040] As Figure 1 、 Figure 3 and Figure 4 shown, the inner wall of the plum blossom-shaped evaporation tube of the spin current has five outwardly convex petal edges and is provided with an inner spiral structure inside the tube. The plum blossom-shaped evaporation tube wall increases the contact area between the fuel and the inner wall of the tube, provides more heat exchange areas under the same pipe size, thereby improving the efficiency of heat transfer and significantly increasing the evaporation rate of the fuel. In a combustion chamber with a compact space, the plum blossom-shaped tube wall can improve the heat exchange efficiency by increasing the inner surface area without increasing the outer diameter of the pipe. This means that under the same space conditions, a higher heat exchange capacity can be achieved, and the design of the plum blossom-shaped tube wall helps to save the volume and material cost of the equipment.

[0041] The fluid is disturbed by the plum-blossom-shaped pipe wall, forming local vortices, which can increase the frequency of fuel hitting the pipe wall, break it into oil droplets, improve the mixing of the fluid, and promote the atomization of the fuel. In addition, the design of the plum-blossom-shaped internal spiral structure can not only cause the air flow to generate a swirling effect along the flow path of the plum-blossom-shaped internal spiral, increasing its contact time with the pipe wall, but also effectively reduce the "dead zone" in the fluid flow process by increasing the disturbance and complexity of the flow (the fluid may form uneven flow regions near the pipe wall or at bends, and due to the too slow or stagnant flow velocity in these regions, the heat exchange efficiency is reduced), making the fluid flow more evenly, thereby significantly improving the heat exchange efficiency. At the outlet of the evaporation pipe, the fuel vapor with a swirling effect is sprayed into the combustion chamber, and the fuel is evenly distributed in the flame area, which not only avoids uneven fuel combustion but also maintains the high-temperature conditions in the reaction zone, thereby improving the flame stability.

[0042] Summarizing the above embodiments, for the plum-blossom-shaped wall internal spiral evaporation pipe of the combustion chamber with self-rotating flow of the present invention, the fluid is guided to spin by the provided support plates and the plum-blossom-shaped wall rotating along the guiding line. The introduction of the self-rotating flow effectively enhances the turbulent effect in the evaporation pipe, enabling the fluid to come into contact with the pipe wall more fully during the flow process and improving the heat transfer efficiency. The rotational movement of the fluid not only increases the mixing of heat inside the fluid but also reduces the formation of the boundary layer through high-frequency disturbance, promoting the uniform distribution of heat in the evaporation pipe. The plum-blossom-shaped wall increases the flow area of the fluid, avoiding dead zones and inefficient regions of the fluid in the pipe, thereby improving the heat exchange efficiency.

[0043] For the plum-blossom-shaped wall internal spiral evaporation pipe of the combustion chamber with self-rotating flow of the present invention, the structure of the plum-blossom-shaped wall helps to more effectively guide the air flow, increasing the contact time between the air flow and the atomized fuel and its contact area with the wall surface, which not only promotes the full mixing of air and fuel but also promotes the evaporation and gasification of the liquid fuel. The self-rotating flow causes strong rotation and disturbance during the fuel flow process, enhancing the uniformity of fuel atomization. Through more uniform atomization, the evaporation efficiency of the fuel is greatly improved, further enhancing the combustion efficiency.

[0044] For the plum-blossom-shaped wall internal spiral evaporation pipe of the combustion chamber with self-rotating flow of the present invention, the plum-blossom-shaped wall structure optimizes the fluid path, enhancing the heat exchange stability of the entire system and reducing phenomena such as knocking, jitter, or incomplete combustion caused by uneven fuel distribution. The rotating jet of the self-rotating flow can form a stable rotating flow field in the combustion area, which can not only promote the full combustion of the fuel but also avoid flame instability caused by excessive air flow disturbance.

[0045] A kind of spiral evaporation tube with plum blossom-shaped wall surface in the combustion chamber of spin current according to the present invention. Micro-aero engines have strict requirements for volume and weight. By adopting the combined design of spin current and plum blossom-shaped wall surface, more efficient heat exchange can be achieved within a limited space, thereby reducing the surface area and volume requirements of the evaporator and the cooling system. In addition, the improved heat exchange efficiency means that lighter materials and more compact structural designs can be used, thereby reducing the weight of the entire system.

[0046] The specific embodiments described above further elaborate on the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the invention. It can also be a reasonable combination of the features described in the above embodiments. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A spiral evaporation tube with a plum blossom-shaped wall in a spinning flow combustion chamber, characterized in that: The invention comprises an oil injection pipe (1), a plurality of support plate blades (2) and an evaporation pipe (3); the oil injection pipe (1) is arranged at the inlet section of the evaporation pipe (3); a plurality of support plate blades (2) are evenly arranged around the oil injection pipe (1); the other end of the support plate blade (2) is connected to the inner wall of the evaporation pipe (3); the radial cross section of the inner wall of the evaporation pipe (3) is in a plum blossom shape and rotates along a guide line.

2. The spiral evaporator tube with a quincunx-shaped wall surface in the swirl flow combustion chamber according to claim 1, characterized in that: The number of petals in the plum blossom shape is 5.

3. The spiral evaporator tube with a quincunx-shaped wall surface in the swirl flow combustion chamber according to claim 2, characterized in that: The plum blossom shape of the inner wall at the outlet of the evaporation tube (3) is rotated clockwise by an angle of 1.5 petal units along the flow direction compared to the plum blossom shape of the inner wall at the inlet.

4. The spiral evaporator tube with a quincunx-shaped wall surface in the swirl flow combustion chamber according to claim 1, 2 or 3, characterized in that: The distance from the center of the circular arc of the plum blossom-shaped petal portion to the axis of the evaporation tube (3) is half the radius of the outer wall of the evaporation tube (3).

5. The spiral evaporation tube with a quincunx-shaped wall surface in the swirl flow combustion chamber according to claim 4, characterized in that: The outer wall radius of the evaporation tube (3) is 9 mm to 10 mm; the radius of the circular arc of the petal part of the plum blossom shape is 3 mm to 4 mm.

6. The spiral evaporation tube with a quincunx-shaped wall surface in the swirl flow combustion chamber according to claim 5, characterized in that: The plum blossom-shaped petals are connected by rounding for smooth transition, and the radius of the rounding is 2 mm to 3 mm.

7. The spiral evaporator tube with a quincunx-shaped wall surface in the swirl flow combustion chamber according to claim 1, characterized in that: The evaporation tube (3) further comprises a transition section and an evaporation section. The inlet section, the transition section and the evaporation section are connected in sequence. The inlet section and the evaporation section are straight tubes, and the transition section is a curved tube.

8. The spiral evaporation tube with a quincunx-shaped wall in the swirl flow combustion chamber according to claim 1, characterized in that: The installation angle of the support plate blades (2) is 10 degrees to 30 degrees.

9. The spiral evaporation tube with a quincunx-shaped wall in the swirl flow combustion chamber according to claim 8, characterized in that: The support plate blade (2) has a thickness of 0.5 mm to 1 mm, and a blade chord length of 8 mm to 10 mm.

10. The spiral evaporation tube with a quincunx-shaped wall in the swirl flow combustion chamber according to claim 1, characterized in that: The inner wall diameter of the fuel injection pipe (1) is 2 mm to 4 mm, and the outer wall diameter is 5 mm to 6 mm.

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