Oil and gas regulation system and method based on variable angle oil injection rod

Abstract

The application discloses an oil-gas regulation system based on a variable-angle oil injection rod, which comprises a force adding cylinder body, a flame stabilizer and an oil injection rod arranged in the force adding cylinder body, wherein the oil injection rod extends along the radial direction of the force adding cylinder body and is located in front of the flame stabilizer, the oil injection rod is provided with a plurality of oil injection holes, the oil injection rod rotates around the radial direction of the force adding cylinder body through a driving device, so that the oil injection direction of the oil injection holes is changed, and the driving device is fixedly arranged on the force adding cylinder body. The oil-gas distribution in a certain area of the force adding combustion chamber is changed through the variable-angle oil injection rod, and the oscillating combustion in the area can be quickly inhibited.

Description

Technical Field

[0001] This invention relates to the afterburner of a gas turbine engine, specifically to a fuel-air control system and method based on a variable-angle fuel injector. Background Technology

[0002] The afterburner is a crucial component of an aero-engine. Under low-oxygen inlet conditions, it re-injects fuel for combustion, thereby generating additional thrust and improving performance. The afterburner experiences harsh inlet conditions, with inlet temperatures typically reaching 1200K, a high heat release rate per unit volume, and complex internal flow. Furthermore, the integrated stabilizer and fuel injector design causes fuel to break up and atomize along the stabilizer wall at the shear layer or be largely entrained behind the stabilizer, resulting in uneven circumferential fuel mist distribution within the combustion chamber and consequently, oscillatory combustion. Oscillatory combustion refers to the positive feedback between pressure pulsations and heat release pulsations within the combustion chamber. Generally, oscillatory combustion is considered to occur when the phase difference between pressure pulsations and heat release pulsations is less than 90°. When oscillatory combustion occurs, it typically causes significant noise from the afterburner, increased heat load, and in severe cases, damage and destruction of system components. Early improvements to the afterburner fuel delivery ring and fuel distribution suppressed some oscillatory combustion, but these also significantly limited the afterburner system's capabilities. With increasing service life, oscillatory combustion problems have recurred, seriously impacting flight safety. Therefore, suppressing oscillating combustion is of great importance.

[0003] Methods for suppressing oscillatory combustion can be broadly categorized into active and passive approaches. Active control typically uses actuators as its core, focusing on altering the excitation source state of oscillatory combustion. Actuators are generally classified into three types: loudspeakers, pulsating nozzles, and distributed actuator layouts. However, existing active control schemes often lack practicality. For example, loudspeaker power is limited, and it's difficult to determine the controlled object, especially since the emitted suppression wave may not be in phase with the disturbance wave, potentially increasing combustion instability. Pulsating nozzles require high precision and are difficult to manufacture, making them prone to coking and carbon buildup under harsh operating conditions. Distributed actuator layouts, while considered the best solution for controlling oscillatory combustion, are currently only in theoretical research. Passive control generally aims to prevent oscillatory combustion by altering the system's natural frequency, such as using resonators and perforated plates. Currently, vibration damping devices are commonly used internationally, suppressing oscillatory combustion through their sound-absorbing properties. However, vibration damping is a passive control method, only reducing the probability of oscillatory combustion to a certain extent. If oscillatory combustion occurs and the excitation source state cannot be adjusted in time, flight safety will remain under threat. Summary of the Invention

[0004] Purpose of the invention: To address the above-mentioned shortcomings, the present invention provides an oil-gas regulation system and method based on a variable angle fuel injector that can suppress oscillating combustion.

[0005] Technical Solution: To solve the above problems, the present invention adopts an oil-gas control system based on a variable angle injection rod, including a booster cylinder. A flame stabilizer and an injection rod are disposed inside the booster cylinder. The injection rod extends radially along the booster cylinder and is located in front of the flame stabilizer. The injection rod is provided with a plurality of injection holes. The injection rod is driven to rotate radially around the booster cylinder, thereby changing the injection direction of the injection holes. The driving device is fixedly disposed on the booster cylinder.

[0006] Furthermore, it also includes several measuring devices and control feedback devices located behind the flame stabilizer. The measuring devices are used to monitor the total temperature and total pressure changes of the afterburner chamber in the afterburner cylinder in real time. The control feedback devices are used to receive the data measured by the measuring devices, process and judge it, and control the operation of the drive device according to the judgment result.

[0007] Furthermore, several injection holes are provided on both sides of the injection rod, and the injection holes are divided into areas. The injection holes in different areas are supplied with fuel independently, while the injection holes in the same area are supplied with fuel simultaneously. The afterburner includes several combustion zones, and the combustion zones correspond one-to-one with the areas divided by the injection holes. Each combustion zone is equipped with a measuring device and a control feedback device.

[0008] Furthermore, the booster cylinder is equipped with a diffuser and a central cone located inside the diffuser. The fuel injector is radially inserted into the diffuser channel of the diffuser 8 and simultaneously inserted into the interior of the central cone, and then protrudes from the interior of the central cone. All fuel injection holes are located between the diffuser and the central cone.

[0009] Furthermore, it also includes a fuel manifold, which is connected to the fuel injector and is used to supply fuel to the fuel injector.

[0010] Furthermore, the flame stabilizer includes several flame stabilizer units, each flame stabilizer unit is provided with several oil injection holes, and the oil injection holes of the flame stabilizer parallel to the oil injection rod and the oil injection holes on the oil injection rod are staggered in the radial direction of the booster cylinder.

[0011] This invention also employs a method for regulating fuel-air mixture based on a variable-angle fuel injector, comprising the following steps:

[0012] Obtain the total temperature and total pressure changes within the afterburner;

[0013] Determine whether oscillating combustion occurs in the afterburner based on changes in total temperature and total pressure.

[0014] When oscillating combustion occurs, the fuel injector is rotated to change the fuel injection direction of the fuel injection holes on the fuel injector, and the fuel injection direction is countercurrent injection.

[0015] Furthermore, the specific steps for determining whether oscillating combustion occurs in the afterburner based on changes in total temperature and total pressure are as follows:

[0016] The changes in total temperature and total pressure are processed into Rayleigh index and total pressure entropy value, which are easy to determine the oscillating combustion state;

[0017] When the afterburner data is abnormal for more than 10 seconds and the Rayleigh index is consistently greater than zero, it is determined that the afterburner is oscillating combustion. The closer the total pressure entropy value is to 0, the more intense the oscillating combustion.

[0018] Furthermore, the rotation angle of the fuel injection rod increases as the entropy value of the total pressure decreases.

[0019] Furthermore, it also includes a fuel branch pipe connected to the fuel main pipe, which is connected to the fuel injection rod. The fuel branch pipe diverts 5% of the total amount of fuel from the fuel main pipe to the oscillating combustion zone for the operation of the fuel injection rod.

[0020] Beneficial Effects: Compared with existing technologies, the significant advantages of this invention are: by altering the fuel-air distribution in a specific area of ​​the afterburner chamber through a variable-angle fuel injector, oscillating combustion within that area can be rapidly suppressed. Compared to other active methods for suppressing oscillating combustion, this invention has a simpler structure and device, minimal impact on flow resistance losses in the afterburner chamber, and utilizes fuel distribution via a fuel branch line, thus not affecting the overall fuel-air ratio in the afterburner chamber. It can monitor changes in the combustion state within the afterburner chamber in real time and quickly identify whether oscillating combustion occurs and its severity. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the variable-angle fuel injection rod in the combustion chamber in this invention;

[0022] Figure 2 This is a cross-sectional schematic diagram of the variable-angle fuel injection rod in the combustion chamber according to the present invention;

[0023] Figure 3 This is a schematic diagram of the variable-angle fuel injector bar with zoned fuel supply in this invention.

[0024] Figure 4 This is a circumferential schematic diagram of the control feedback device and measuring device in this invention;

[0025] Figure 5 This is a schematic diagram of the variable-angle fuel injector in operation according to the present invention. Detailed Implementation

[0026] like Figure 1As shown, this embodiment of an oil-gas control system based on a variable-angle fuel injector includes a variable-angle fuel injector 1, a rotary motor 2, a flame stabilizer 6, a measuring device 4 installed behind the flame stabilizer, a control feedback device 3, and a fuel system. The variable-angle fuel injector 1 is located in front of the flame stabilizer 6, radially inserted into the diffuser channel of the diffuser 8, and then inserted into the central cone before exiting from the inside of the central cone. The rotary motor 2 is connected to the variable-angle fuel injector 1 and is fixedly installed on the booster cylinder 7. The fuel manifold 5 is connected to the variable-angle fuel injector 1 and covers a flexible channel to achieve simultaneous operation of rotation and fuel supply.

[0027] like Figure 2 As shown, in this embodiment, the variable-angle injection rod 1 has 20 uniformly arranged jet injection holes with a diameter of 0.75mm on both sides. When no oscillating combustion occurs, the injection rod is at its initial working angle. At this time, the injection direction of the injection holes on the injection rod is perpendicular to the airflow direction and begins to change after receiving a response. The injection holes and the injection holes on the same side of the flame stabilizer are staggered to ensure that when adjusting the fuel-air ratio in the afterburner, there will be no greater uneven fuel mist in the circumferential direction, which would aggravate oscillating combustion. At the same time, the variable-angle injection rod 1 adopts zoned fuel supply, independently supplying fuel to the injection holes in different areas, while the injection holes in the same area are supplied with fuel simultaneously, such as... Figure 3 As shown, the variable-angle fuel injector 1 has a fuel supply zone division that corresponds to the combustion chamber zone division, so as to accurately supply fuel to the oscillating combustion zone individually.

[0028] like Figure 4 As shown, in this embodiment, a control feedback device 3 and a measuring device 4 are used to monitor the combustion state inside the afterburner in real time. The measuring device 4 consists of at least one set of total pressure probes and total temperature probes, with a total of four sets in the circumferential direction. It extends radially from the afterburner and is placed behind the flame stabilizer, dividing the afterburner into four zones: I, II, III, and IV. When oscillating combustion occurs in a certain zone, the flame and pressure in that zone will change periodically, and the other zones will be affected to varying degrees. The control feedback device 3 receives the data measured by the measuring device 4 and makes a judgment. The zone with the most obvious data anomaly is the zone where oscillating combustion occurs.

[0029] In actual operation, the four sets of measuring devices 4 behind the flame stabilizer monitor the changes in total temperature and total pressure in the afterburner in real time. The data is collected and processed by the control feedback device 3 to form the Rayleigh index and the arrangement entropy value of the total pressure, which are easy to use to determine the oscillating combustion state. Based on the principle that a Rayleigh index continuously greater than zero indicates that the heat release energy from combustion can continuously inject energy into the sound field and maintain the oscillating combustion phenomenon, when the control feedback device 3 receives abnormal data from a certain area of ​​the afterburner for more than 10 seconds and the Rayleigh index remains continuously greater than zero, it indicates that oscillating combustion has occurred in that area. The control feedback device 3 then activates the rotary motor to start the variable-angle fuel injector 1. At this time, the fuel branch pipe 5 diverts 5% of the total fuel from the fuel main pipe to the oscillating combustion area for the variable-angle fuel injector, thus ensuring that the total air-fuel ratio is not affected while changing the air-fuel distribution in the oscillating combustion area.

[0030] like Figure 5 As shown, when oscillating combustion occurs in zone I of the combustion chamber, the control feedback device 3 activates the variable-angle fuel injector 1 to begin operation in zone I. The fuel injection direction is counter-current injection, and the rotation angle changes with the arrangement entropy value of the total pressure. The arrangement entropy value is a dimensionless parameter ranging from 0 to 1. According to the rule that the closer the arrangement entropy value of the total pressure is to 0, the more intense the oscillating combustion in that zone, the greater the rotation angle. Typically, counter-current injection has a longer delay time and a larger diffusion angle, resulting in a more uniform fuel distribution in that zone and improved combustion stability, thus suppressing oscillating combustion.

[0031] In existing technologies, the integrated stabilizer and fuel injector design of afterburners can cause fuel to break up and atomize along the stabilizer wall at the shear layer, or a large amount to be entrained behind the stabilizer. This results in uneven circumferential fuel mist distribution in the combustion chamber, and the coupling of vortex shedding at a specific frequency behind the radial stabilizer with uneven combustion heat release can lead to oscillating combustion, which can cause significant structural damage. Therefore, this embodiment employs a method that can monitor changes in combustion conditions within the afterburner in real time and uses collected data to determine whether oscillating combustion has occurred. When abnormal data persists for 10 seconds, the fuel-air distribution within the afterburner is adjusted in real time using a variable-angle fuel injector to suppress the continued occurrence of oscillating combustion.

Claims

1. A fuel-air control system based on a variable angle fuel injector, characterized in that, Includes a booster cylinder (7), inside which is provided a flame stabilizer (6) and an oil spray rod (1). The oil spray rod (1) extends radially along the booster cylinder (7) and is located in front of the flame stabilizer. The oil spray rod is provided with several oil spray holes. The oil spray rod is driven by a drive device to rotate radially around the booster cylinder (7), thereby changing the oil spray direction of the oil spray holes. The drive device is fixedly installed on the booster cylinder (7). It also includes several measuring devices (4) and a control feedback device (3) located behind the flame stabilizer. The measuring devices (4) are used to monitor the total temperature and total pressure changes in the afterburner chamber inside the afterburner cylinder (7) in real time. The control feedback device (3) is used to receive the data measured by the measuring devices (4), process and judge it, and control the operation of the drive device according to the judgment result. The fuel injector (1) has several fuel injector holes on both sides. The fuel injector holes are divided into regions. The fuel injector holes in different regions are supplied with fuel independently. The fuel injector holes in the same region are supplied with fuel simultaneously. The afterburner includes several combustion regions. The combustion regions correspond one-to-one with the regions divided by the fuel injector holes. Each combustion region is equipped with a measuring device and a control feedback device.

2. The oil and gas regulation system according to claim 1, characterized in that, The booster cylinder (7) is provided with a diffuser (8) and a central cone located inside the diffuser (8). The fuel injector (1) is radially inserted into the diffusion channel of the diffuser (8) and simultaneously inserted into the interior of the central cone, and then passes out from the interior of the central cone. The fuel injection holes are all located between the diffuser (8) and the central cone.

3. The oil and gas regulation system according to claim 1, characterized in that, It also includes a fuel manifold (5), which is connected to the fuel injector (1) and is used to supply fuel to the fuel injector (1).

4. The oil and gas regulation system according to claim 3, characterized in that, The flame stabilizer includes several flame stabilizer units, each flame stabilizer unit is provided with several oil injection holes, and the oil injection holes of the flame stabilizer units parallel to the oil injection rod and the oil injection holes on the oil injection rod are staggered in the radial direction of the booster cylinder (7).

5. A method for controlling oil and gas based on a variable angle injection rod using the oil and gas control system according to any one of claims 1 to 4, characterized in that, Includes the following steps: Obtain the total temperature and total pressure changes within the afterburner; Determine whether oscillating combustion occurs in the afterburner based on changes in total temperature and total pressure. When oscillating combustion occurs, the fuel injector is rotated to change the fuel injection direction of the fuel injection holes on the fuel injector, and the fuel injection direction is countercurrent injection.

6. The oil and gas regulation method according to claim 5, characterized in that, The specific steps for determining whether oscillating combustion occurs in the afterburner based on changes in total temperature and total pressure are as follows: The changes in total temperature and total pressure are processed into Rayleigh index and total pressure entropy value, which are easy to determine the oscillating combustion state; When the afterburner data is abnormal for more than 10 seconds and the Rayleigh index remains greater than zero, it is determined that the afterburner is oscillating combustion. The closer the total pressure entropy value is to 0, the more intense the oscillating combustion.

7. The oil and gas regulation method according to claim 6, characterized in that, The rotation angle of the fuel injector increases as the entropy value of the total pressure decreases.

8. The oil and gas regulation method according to claim 6, characterized in that, It also includes a fuel branch pipe (5) connected to the fuel main pipe, the fuel branch pipe (5) is connected to the fuel injector (1), and the fuel branch pipe (5) divides 5% of the total amount of fuel in the oscillating combustion area from the fuel main pipe for the operation of the fuel injector.

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