Rotational flow combustion chamber with rotatable blades

Abstract

The invention discloses a rotational flow combustion chamber with rotatable blades, and relates to the field of design and application of aero-engine combustion chamber models. The blades of the cyclone are driven by an external electric driving device to rotate around the shaft, so that real-time continuous adjustment of the rotational flow strength and form is realized, and the requirements of combustion stability and thermal load distribution under different working conditions are met. The swirler is arranged at the air inlet end of the combustion chamber casing and comprises a hub, a center shaft and a plurality of swirler blades, the hub is fixedly installed at the air inlet end of the combustion chamber casing, the center shaft is rotatably installed in the hub, and the swirler blades are arranged on the center shaft. The roots of the swirler blades are mounted on the central shaft through a connecting structure with an adjustable rotating angle; a shell of the motor is fixedly installed on one side of the cyclone through a supporting support, and an output shaft of the motor is connected with the center shaft through a heat-resisting coupler. The stability and response adaptability of the combustion chamber under multiple working conditions can be remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of aero-engine combustion chamber model design and application. Background Technology

[0002] In the field of combustion design for aero-engines, gas turbines, and high-performance propulsion systems, combustion efficiency, flame stability, and thermal uniformity are core indicators for evaluating combustor performance. Modern combustors typically operate in high-temperature, high-pressure, and high-load-variation environments, placing higher demands on their stable operation. Traditional combustors often employ fixed-structure swirlers, relying on geometric parameters (such as blade angle, spacing, and number) to preset the swirling intensity, thereby enhancing air-fuel mixing efficiency and maintaining flame stability. However, with the increasing demands for engine adaptability, fixed-structure swirlers have significant limitations when facing complex operating conditions, necessitating the development of novel combustion structures with dynamic adjustment capabilities.

[0003] Swirl combustion technology is an effective means to improve combustion efficiency, reduce flame propagation distance, and promote thorough fuel-air mixing. Swirlers introduce angular momentum, causing the air entering the combustion chamber to rotate around its axis, thus creating a low-pressure recirculation zone at the center of the combustion chamber. This is beneficial for stable flame anchoring and self-excited heat feedback. Simultaneously, swirl increases the shear interface, promotes turbulent mixing, and accelerates the reaction rate between fuel and oxidizer. Traditional swirlers often employ static blade structures, requiring designs that ensure maximum swirl effect under high operating conditions while also considering stability under low operating conditions. However, during the wide range of variable operating conditions covered within the flight envelope, a fixed swirl intensity often fails to meet the combustion stability and efficiency requirements at all stages. Taking a civil turbofan engine as an example, its combustion chamber typically undergoes multiple operating states, including start-up, lubricating oil preheating, ground acceleration, takeoff, cruise, and glide, with significantly different combustion requirements at each stage. For example, during startup and low-speed coasting, excessively strong swirling can cause flame drift or even flameout, while during high-load operation, stronger swirling is needed to suppress localized high-temperature areas and improve mixing uniformity. The inability to simultaneously achieve optimal performance of fixed swirlers under different operating conditions has prompted researchers to seek solutions with adjustable swirling structures.

[0004] In recent years, some studies have attempted to improve swirl control capabilities through multi-channel or multi-stage swirlers. For example, Chinese invention patent application "A Two-Stage Swirler Adjustable Variable Geometry Combustion Chamber" (application number 202310157835.7) can automatically adjust the outlet geometric area of ​​the middle and outer swirlers according to the incoming flow temperature, thereby achieving automatic adjustment of the air intake at the flame tube head. An adaptive air intake device enables variable air intake geometry in the combustion chamber, ensuring ignition start-up and combustion stability. Chinese invention patent application "A Nozzle, Nozzle Array, and Combustion Burner with Adjustable Swirl Number and Turbulence Intensity" (publication number CN106907709A) adjusts the swirl number and turbulence intensity by rotating the middle or outer cylinder to adjust the relative position between the inner and outer blades of the swirler. However, this structure is complex, costly to manufacture, and still cannot achieve continuous blade angle adjustment, limiting its control capability. Another approach is to use movable parts or smart materials to change the intake direction, but due to limitations in structural strength, high-temperature durability, and response rate, it is difficult to widely apply this to the main combustion zone.

[0005] On the other hand, the application of electric drive and intelligent control technologies in high-temperature structures has matured in recent years, providing new opportunities for the dynamic control of swirling structures. Swirl structures driven by electric motors and couplings can achieve real-time adjustment of rotational angular velocity, thereby indirectly controlling the swirling intensity. Furthermore, if the blade installation angle or shape is designed to be adjustable, a broader range of swirling morphology control can be achieved, encompassing axial + radial composite swirling, eccentric swirling, and other forms, offering greater freedom. Therefore, there is an urgent need for a novel swirling control method that is simple in structure, has a fast response, and is highly adaptable. Summary of the Invention

[0006] To address the above problems, this invention proposes a swirling combustion chamber with rotatable blades. An external electric drive device drives the swirler blades to rotate around an axis, enabling real-time and continuous adjustment of the swirling intensity and morphology, thereby adapting to the requirements of combustion stability and heat load distribution under different operating conditions.

[0007] The technical solution of the present invention is as follows: the swirling combustion chamber includes a combustion chamber casing 4, a swirler, a motor 2, a heat-resistant coupling 7, and a support bracket 1; The combustion chamber casing 4 is equipped with a nozzle 3 on its side wall. The combustion chamber casing 4 is equipped with a swirler at its air intake end. The swirler includes a hub 6, a central shaft 14, and several swirler blades 8. The hub 6 is fixedly installed at the air intake end of the combustion chamber casing 4. The central shaft 14 is rotatably installed in the hub 6. The roots of several swirler blades 8 are installed on the central shaft 14 through an adjustable rotation angle connection structure. The housing of the motor 2 is fixedly mounted on one side of the hydrocyclone by a support bracket 1, and the output shaft of the motor 2 is connected to the central shaft 14 by a heat-resistant coupling 7.

[0008] Furthermore, the intake end of the combustion chamber casing 4 is connected to the intake casing 9, and a sealing cover 10 is fixedly installed on the side wall of the intake casing 9. One end of the support bracket 1 is fixedly connected to the sealing cover 10, and the other end is fixedly connected to the housing of the motor 2.

[0009] Furthermore, the adjustable angle connection structure is as follows: The hydrocyclone blade 8 is mounted on a spring plate 11 via a fulcrum at its root, enabling it to rotate around the coupling. One side of the spring plate 11 is fixedly connected to a support rib 12, which is fixedly mounted on a central shaft 14. A spring 13 is also provided between the middle of the spring plate 11 and the support rib 12. During adjustment, the motor rotates, applying torque to the hydrocyclone blade 8, causing the blade root to rotate around the coupling, thus adjusting the angle. During rotation, the spring plate 11 and spring 13 deform and provide a reaction force, changing the angle of the hydrocyclone blade 8. When the external force is released, the elastic force of the spring plate 11 and spring 13 allows the blade to automatically return to its initial position, thereby realizing the adjustable and reset function of the hydrocyclone blade 8 angle.

[0010] Furthermore, the motor 2 is a servo motor or a stepper motor, and is equipped with a speed control module to achieve precise adjustment of the blade rotation speed.

[0011] Furthermore, the cyclone blades 8 are made of high-temperature alloy material, and their surfaces are provided with cooling channels or coated with ceramic thermal barrier coatings to improve high-temperature durability.

[0012] Furthermore, the nozzle 3 is an axial atomizing nozzle and is located at the center of the combustion chamber casing 4, which can form a good radial mixing zone with the swirling air to achieve high-efficiency atomized combustion.

[0013] The hydrocyclone blade 8 is a rotatable blade, and its rotation speed can be changed in real time by the motor 2.

[0014] The cyclone blades 8 can be disassembled through a quick-release mechanism when not in operation, allowing for rapid replacement of blade structures of different sizes, quantities, or bending angles to adapt to different combustion research conditions.

[0015] This invention not only retains the stability and mixing advantages of traditional cyclones, but also introduces moving parts to enhance its intelligent response capabilities. It can be widely applied in variable-condition combustion systems, experimental controllable combustion platforms, and high-efficiency, low-emission propulsion systems. This invention possesses significant originality and engineering application value, and has broad prospects in areas such as variable-condition combustion efficiency optimization, dynamic flame stability control, and high-performance propulsion configurations.

[0016] Compared with the prior art, the present invention has the following significant advantages: 1. To achieve dynamic rotation adjustment of the hydrocyclone blades and have the ability to control the variable swirling airflow speed; Second, it can significantly improve the stability and responsiveness of the combustion chamber under various operating conditions; Third, the structure is compact, and the motor is far away from the combustion zone, which provides good thermal isolation and mechanical reliability. IV. Applicable to engineering applications of cyclone performance research, flame structure control, and high-performance low-emission combustion systems; V. The hydrocyclone is replaceable, facilitating experimental replacement and maintenance. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the combustion chamber; Figure 2 This is a schematic diagram of the combustion chamber cross-section; Figure 3 This is a schematic diagram of the motor assembly; Figure 4 This is a schematic diagram of a rotatable hydrocyclone; Figure 5 This is a schematic diagram of the intake casing; Figure 6 This is a diagram of a shrapnel. Figure 7 It is a connection structure with adjustable rotation angle; In the diagram: 1 is the support bracket, 2 is the motor, 3 is the nozzle, 4 is the combustion chamber casing, 5 is the screw, 6 is the hub, 7 is the heat-resistant coupling, 8 is the cyclone blade, 9 is the intake casing, 10 is the sealing cover, 11 is the spring, 12 is the support rib, 13 is the spring, and 14 is the central shaft. Detailed Implementation

[0018] To clearly illustrate the technical features of the present invention, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

[0019] Given that existing combustion chamber structures typically employ fixed-angle blades in swirlers, resulting in unadjustable swirling intensity, they struggle to meet the dynamic performance requirements of flame structure, mixing efficiency, and heat load distribution under various engine operating conditions. Furthermore, swirlers with fixed structures cannot precisely control the fuel-air mixing scale under different operating states, easily leading to problems such as localized high-temperature hotspots, flame drift, or flameout, severely impacting combustion stability and engine safety margins. While some existing solutions attempt to improve adaptability through multi-channel swirling designs or passive adjustment methods, their complex structures, slow response times, and high manufacturing and control difficulties make reliable operation in high-temperature, high-speed environments challenging.

[0020] The technical solution adopted in this invention is a swirling combustor with rotatable blades. Its structure includes: a combustor casing 4, a nozzle 3, swirler blades 8, a hub 6, a motor 2, a heat-resistant coupling 7, a support bracket 1, and an intake casing 9. The swirler is installed at the inlet end of the combustor casing 4, the nozzle 3 is installed on the combustor casing 4, and the swirler blades 8 are designed to rotate with the drive shaft. The motor 2 drives the central shaft 14 and the coupling 7 to achieve real-time controllable rotation of the swirler blades 8, thereby changing the airflow injection angle and adjusting the swirling intensity and recirculation zone morphology. The motor 2 and the swirler are connected by the heat-resistant coupling 7 to ensure long-term stable operation of the electric system in high-temperature environments. This structure allows for real-time adjustment of the airflow rotation speed according to different operating conditions. At low loads, the swirling is weakened to prevent flame backflow or extinguishing; at high loads, the swirling is enhanced to improve mixing efficiency and suppress the distribution of high-temperature hot spots, thus achieving synergistic optimization of flame stability and outlet temperature uniformity under different combustion conditions. In addition, the device has a compact structure, which facilitates integration with existing combustion chamber nozzles and casing structures, and is suitable for a variety of experimental or engineering combustion systems.

[0021] Specifically: The combustion chamber casing 4 is rectangular and made of high-temperature resistant alloy material. Nozzle 3 is located above the combustion chamber casing 4 and connected to the fuel supply system to atomize fuel and inject it into the swirling air to form a combustible mixture. Nozzle 4 can be a single-hole or multi-hole structure. A swirler is installed at the inlet of the combustion chamber casing 4, with 6–12 blades made of high-temperature resistant stainless steel or nickel-based alloy. Each blade is installed inside a hub 6, which is fixed to the combustion chamber casing 4 by screws 5. The swirler blades 8 are connected to the central shaft 14 via an adjustable-angle connection structure, allowing the entire assembly to rotate with the shaft, forming a variable-speed swirling airflow. Motor 2 is installed outside the combustion chamber and connected to the central shaft 14 via a heat-resistant coupling 7, driving the swirler blades 8 to rotate as a whole. Motor 2 is a high-precision stepper or servo motor, enabling precise speed control. Support bracket 1 securely mounts motor 2 to the external platform, ensuring that the drive system is axially concentric with the combustion chamber. The bracket is made of high-strength aluminum alloy and has an anodized surface for corrosion protection. The support bracket 1 is fixed to the intake casing 9 and sealed by the sealing cover 10.

[0022] Working principle: When air enters from the front of the combustion chamber, it forms a tangential velocity component through the swirler blades, generating a strong swirling flow. The motor drives the entire swirler blade to rotate, changing the relative velocity between the incoming airflow and the blades, thereby adjusting the swirling intensity (Swirl Number). Higher velocities enhance the recirculation zone and mixing efficiency, suitable for high-load combustion; lower velocities weaken the swirling intensity, preventing flame backflow or flameout under low loads. Under different operating conditions (such as start-up, stable combustion, and partial load), the control system can adjust the blade rotation speed in real time, achieving dynamic optimization of the swirling degree and flame structure, improving combustion efficiency and temperature field uniformity, and suppressing the formation of localized high-temperature hotspots.

[0023] How to use: Install the swirler to the combustion chamber casing and secure the nozzle and motor; connect the motor, heat-resistant coupling, and central shaft, ensuring alignment of the rotation center, and connect to the support bracket; input different rotation commands, and the motor drives the swirler to achieve the predetermined speed setting; introduce air and fuel, and adjust the swirling speed after ignition by temperature measurement feedback; perform multiple adjustments or programmed control according to different operating conditions, and collect combustion characteristic data.

[0024] There are many specific ways to implement this invention. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A swirl combustion chamber with rotatable vanes, characterized in that The cyclone combustion chamber comprises a combustion chamber casing (4), a cyclone, a motor (2), a heat-resistant coupling (7) and a support bracket (1); A nozzle (3) is mounted on the side wall of the combustion chamber casing (4), and the cyclone is arranged at the air inlet end of the combustion chamber casing (4), the cyclone comprises a hub (6), a central shaft (14) and a plurality of cyclone blades (8), the hub (6) is fixedly installed at the air inlet end of the combustion chamber casing (4), the central shaft (14) is rotatably installed in the hub (6), and the roots of the plurality of cyclone blades (8) are installed on the central shaft (14) through an adjustable angle connecting structure. The shell of the motor (2) is fixedly installed beside the cyclone through the support bracket (1), and the output shaft of the motor (2) is connected with the central shaft (14) through the heat-resistant coupling (7).

2. A swirl combustion chamber with rotatable vanes according to claim 1, characterized in that The air inlet end of the combustion chamber casing (4) is connected with the air inlet casing (9), a sealing cover (10) is fixedly installed on the side wall of the air inlet casing (9), one end of the support bracket (1) is fixedly connected with the sealing cover (10), and the other end is fixedly connected with the shell of the motor (2).

3. A swirl combustion chamber with rotatable vanes according to claim 1, characterized in that The adjustable angle connecting structure is that the cyclone blade (8) is installed on the spring sheet (11) through the fulcrum at the root, one side of the spring sheet (11) is fixedly connected with the support rib (12), the support rib (12) is fixedly installed on the central shaft (14), and a spring (13) is arranged between the middle part of the spring sheet (11) and the support rib (12).

4. A swirl combustion chamber with rotatable vanes according to claim 1, characterized in that The motor (2) is a servo motor or a stepping motor, and is provided with a speed control module.

5. A swirl combustion chamber with rotatable vanes according to claim 1, wherein The cyclone blade (8) is made of high-temperature alloy material, and a cooling channel is arranged on the surface of the cyclone blade (8) or a ceramic thermal barrier coating is coated on the surface of the cyclone blade (8).

6. A swirl combustion chamber with rotatable vanes according to claim 1, wherein The nozzle (3) is an axial atomizing nozzle, and is located at the central position of the combustion chamber casing (4).

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