A collapsing rotary detonation combustion device

Abstract

This invention relates to a contraction-type rotary detonation combustion device, belonging to the technical field of combustion equipment. It includes an inner cylinder, an outer cylinder, and multiple mixing components. The outer cylinder is spaced outside the inner cylinder, defining an annular airflow channel. The multiple mixing components are distributed circumferentially, and each component includes a support rod, a flow divider, a hydrogen cylinder, and an integrally formed air cylinder, cone, and combustion cylinder. The flow divider is located in the middle of the cone to split the airflow in two and accelerate it. A hydrogen port is provided at the connection between the cone and the combustion cylinder, and the hydrogen cylinder is vertically connected to the hydrogen port. This invention first uses a contraction-type flow divider to split and accelerate the airflow, and then uses the hydrogen airflow introduced through the hydrogen cylinder to orthogonally collide with the accelerated airflow, forming a stable vortex. This achieves efficient, low-pressure-loss, and uniform mixing over a short distance. Simultaneously, the high-speed airflow's envelopment and shearing of the hydrogen jet effectively suppresses backfire, providing ideal incoming flow conditions for reliable initiation and self-sustaining propagation of the detonation wave.

Description

Technical Field

[0001] This invention relates to the field of combustion equipment technology, and in particular to a shrinking rotary detonation combustion device. Background Technology

[0002] Rotating detonation combustors (RDCs), based on detonation combustion, offer significant advantages such as pressure gain, self-pressurization, rapid heat release, low entropy production, and compact structure. Their detonation cycle thermal efficiency can be increased by approximately 30%–40% compared to traditional isobaric combustion cycles. Successful application in industrial gas turbines would dramatically improve cycle thermal efficiency, profoundly impacting the entire power machinery field. In the engineering process of RDCs, the cold-state mixing quality of fuel and oxidizer directly determines the initiation and self-sustaining stability of the detonation wave. However, non-premixed RDC flow fields commonly exhibit large-scale eddies and recirculation instabilities, easily leading to increased mixing inhomogeneity and backfire risk. This weakens the detonation wave propagation speed, detonation efficiency, and pressure gain potential, and in severe cases, even causes separation between the reaction zone and the shock wave surface.

[0003] To improve mixing, reduce pressure loss, and suppress backfire, researchers have conducted extensive work on optimizing injection structures. For example, Qi et al. found through numerical simulations that the injection position of a converging inlet significantly affects mixing characteristics; injecting hydrogen during the subsonic acceleration phase of the converging section can effectively reduce the total pressure loss in the combustion chamber dome region. However, firstly, existing converging inlets typically achieve airflow acceleration only through changes in channel area, lacking coordinated design with fuel injection position and local recirculation organization; while conventional bluff body structures can form a recirculation zone, they easily introduce significant separation losses. Secondly, conventional bluff body structures easily induce airflow separation and additional drag, resulting in increased total pressure loss. Thirdly, limited by mixing time and flow field organization, it is difficult to form stable recirculation vortices to enhance mixing under orthogonal jet conditions, thus restricting further improvements in mixing efficiency.

[0004] Therefore, how to design a shrinking rotary detonation combustion device with good mixing effect, low total pressure loss of gas flow and strong anti-backfire performance has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This invention provides a shrinking rotary detonation combustion device, which solves the technical problems of poor mixing effect, large total pressure loss of gas flow and weak backfire prevention performance of existing detonation combustion devices.

[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: a shrinking rotary detonation combustion device, comprising: an inner cylinder, an outer cylinder, and multiple mixing components; the outer cylinder is gapped outside the inner cylinder and defines an annular airflow channel between the outer cylinder and the inner cylinder; the multiple mixing components are sequentially distributed in the airflow channel along the circumferential direction, and each mixing component includes a support rod, a distributor, a hydrogen cylinder, and an air cylinder, a cone, and a combustion cylinder integrally formed along the axial direction of the airflow channel; the air cylinder, the cone, and the combustion cylinder are all fixed outside the inner cylinder and the outer cylinder. The outer cylinder is arranged with the small end of the cone facing the combustion cylinder; the support rod is arranged perpendicular to the axial direction of the cone and one end is fixed to the inner wall of the cone; the fluid divider is located in the middle of the cone and fixed to the other end of the support rod to divide the airflow in the cone into two and accelerate the separated airflow; a hydrogen port is provided at the connection between the cone and the combustion cylinder; the hydrogen cylinder is arranged perpendicular to the combustion cylinder and connected to the hydrogen port to introduce hydrogen flow into the hydrogen port, so that the hydrogen flow and the air flow collide orthogonally to form a backflow vortex.

[0007] The beneficial effects of this invention are as follows: First, the airflow is divided into two by a flow divider located in the middle of the cone, and the velocity of the separated airflows is accelerated. Then, a hydrogen cylinder is used to connect the hydrogen port at the junction of the cone and the combustion cylinder, so that the accelerated airflow collides orthogonally with the vertically injected hydrogen flow. This helps to form a backflow zone, prolongs the local residence time of hydrogen and air, and achieves efficient and uniform mixing over a short distance, providing ideal incoming flow conditions for reliable initiation and self-sustaining propagation of the detonation wave. In addition, the high-speed airflow's enveloping and shearing effect on the hydrogen jet can effectively suppress the tendency of hydrogen to flashback upstream, improving the operational safety of the device under a wide range of operating conditions.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, the flow divider is an arc-shaped structure arranged circumferentially along the airflow channel, and its cross-sectional thickness gradually decreases from near the air cylinder to near the combustion cylinder. The side of the flow divider corresponding to the air cylinder is rounded and the other side corresponding to the combustion cylinder is pointed, so as to reduce the local separation and additional resistance of the airflow on the side of the flow divider and reduce the total pressure loss caused by abrupt flow around.

[0010] The further beneficial effects of adopting the above are: the side of the splitter facing the air cylinder adopts a smooth transition design, which can guide the airflow to split smoothly and avoid local separation of airflow caused by geometric changes, thereby reducing the flow resistance of the inlet section; at the same time, the splitter gradually shrinks towards the combustion cylinder and eventually forms a pointed trailing edge, which allows the split airflow to merge smoothly and accelerate through, effectively suppressing the additional resistance and energy dissipation caused by trailing edge vortex shedding and abrupt flow around.

[0011] Furthermore, the width of the air cylinder is 3 to 4 times the width of the reflux vortex.

[0012] Furthermore, the width of the air cylinder is 4.0 to 5.0 mm.

[0013] Furthermore, the width of the combustion cylinder is 1.0mm to 2.0mm.

[0014] The further beneficial effects of adopting the above are: limiting the diameter of the combustion tube to 1.0mm to 2.0mm, combined with the diversion and acceleration effect of the airflow, the local flow area after diversion is further reduced to less than 1.0mm. According to the principle of quenching distance, this size is smaller than the critical diameter of the hydrogen-air premixed gas under local operating conditions, thereby forming a natural "pneumatic quenching" barrier in the inlet section of the combustion tube, which completely blocks the back path of the flame to the upstream cone and air cylinder from a structural point of view.

[0015] Furthermore, the width of the hydrogen cylinder is 0.05–0.08 mm. Attached Figure Description

[0016] Figure 1 This is a side view of a shrinkable rotary detonation combustion device according to the present invention;

[0017] Figure 2 This is a schematic diagram of the internal structure of the mixing component in a shrinkable rotary detonation combustion device according to the present invention; Figure 3 This is a three-dimensional structural diagram of the fluid distribution in a shrinkable rotary detonation combustion device according to the present invention; Figure 4 This is a diagram illustrating the internal airflow of the mixing component in a shrinking rotary detonation combustion device according to the present invention.

[0018] The attached diagram lists the components represented by each number as follows: 1. Inner cylinder, 2. Outer cylinder, 3. Blending assembly, 31. Support rod, 32. Flow divider, 33. Hydrogen cylinder, 34. Air cylinder, 35. Conical cylinder, 36. Combustion cylinder. Detailed Implementation

[0019] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0020] like Figure 1 and Figure 2 As shown, a shrinking rotary detonation combustion device includes: an inner cylinder 1, an outer cylinder 2, and multiple mixing components 3. The outer cylinder 2 is spaced outside the inner cylinder 1 and defines an annular airflow channel between the outer cylinder 2 and the inner cylinder 1. The multiple mixing components 3 are sequentially distributed in the airflow channel along its circumferential direction. Each mixing component 3 includes a support rod 31, a distributor 32, a hydrogen cylinder 33, and an air cylinder 34, a cone 35, and a combustion cylinder 36 integrally formed along the axial direction of the airflow channel. The air cylinder 34, the cone 35, and the combustion cylinder 36 are all fixed outside the inner cylinder 1 and inside the outer cylinder 2. The small end of the cone 35 is arranged facing the combustion cylinder 36; the support rod 31 is arranged along the axial direction perpendicular to the cone 35 and one end is fixed to the inner wall of the cone 35; the separator 32 is located in the middle of the cone 35 and fixed to the other end of the support rod 31 to divide the airflow in the cone 35 into two and accelerate the separated airflow; a hydrogen port is provided at the connection between the cone 35 and the combustion cylinder 36; the hydrogen cylinder 33 is arranged perpendicularly to the combustion cylinder 36 and connected to the hydrogen port to introduce hydrogen flow into the hydrogen port, so that the hydrogen flow and the air flow collide orthogonally to form a backflow vortex.

[0021] like Figure 3 As shown, in some specific embodiments, the splitter 32 is an arc-shaped structure arranged circumferentially along the airflow channel, and its cross-sectional thickness gradually decreases from near the air cylinder 34 to near the combustion cylinder 36. The side of the splitter 32 corresponding to the air cylinder 34 is rounded and the other side corresponding to the combustion cylinder 36 is pointed, so as to reduce the local separation and additional resistance of the airflow on one side of the splitter 32 and reduce the total pressure loss caused by abrupt flow around.

[0022] Specifically, the width of the air cylinder 34 can be 3 to 4 times the width of the reflux vortex.

[0023] Specifically, the width of the air cylinder 34 can be 4.0 to 5.0 mm.

[0024] Specifically, the width of the combustion tube 36 can be 1.0mm to 2.0mm.

[0025] Specifically, the width of the hydrogen cylinder 33 can be 0.05 to 0.08 mm.

[0026] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A collapsing rotary detonation combustion device, characterized by, include: Inner cylinder (1) and outer cylinder (2), wherein the outer cylinder (2) is fitted outside the inner cylinder (1) with a gap and defines an annular airflow channel between the outer cylinder (2) and the inner cylinder (1); Multiple mixing components (3) are arranged sequentially in the circumferential direction of the airflow channel. Each mixing component (3) includes a support rod (31), a separator (32), a hydrogen cylinder (33), and an air cylinder (34), a cone (35), and a combustion cylinder (36) integrally formed along the axial direction of the airflow channel. The air cylinder (34), the cone (35), and the combustion cylinder (36) are all fixed outside the inner cylinder (1) and inside the outer cylinder (2), with the small end of the cone (35) facing the combustion cylinder (36). The support rod (31) is perpendicular to the airflow channel. The cone (35) is axially arranged and one end is fixed to the inner wall of the cone (35); the splitter (32) is located in the middle of the cone (35) and fixed to the other end of the support rod (31) to split the airflow in the cone (35) into two and accelerate the separated airflow; a hydrogen port is provided at the connection between the cone (35) and the combustion cylinder (36); the hydrogen cylinder (33) is arranged perpendicularly to the combustion cylinder (36) and connected to the hydrogen port to introduce hydrogen flow into the hydrogen port, so that the hydrogen flow and the air flow collide orthogonally to form a backflow vortex.

2. A collapsing rotary detonation combustion device according to claim 1, wherein, The flow divider (32) is an arc-shaped structure arranged circumferentially along the airflow channel, and its cross-sectional thickness gradually decreases from the direction near the air cylinder (34) to the direction near the combustion cylinder (36). The flow divider (32) is rounded on one side corresponding to the air cylinder (34) and pointed on the other side corresponding to the combustion cylinder (36) to reduce the local separation and additional resistance of the airflow on the side of the flow divider (32) and reduce the total pressure loss caused by abrupt flow around.

3. A collapsing rotary detonation combustion device according to claim 1, wherein, The diameter of the air cylinder (34) is 3 to 4 times the width of the reflux vortex.

4. The collapsing rotating detonation combustor of claim 1, wherein, The width of the air cylinder (34) is 4.0 to 5.0 mm.

5. The collapsing rotating detonation combustor of claim 1, wherein, The width of the combustion tube (36) is 1.0 mm to 2.0 mm.

6. A collapsing rotary detonation combustion device according to claim 1, wherein, The width of the hydrogen cylinder (33) is 0.05 to 0.08 mm.

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