Adjustable guide vane control system, control method and internal combustion engine

Abstract

A guide vane control system comprises an ECU (Electronic Control Unit), a PID (Proportion Integration Differentiation) controller, a PWM (Pulse Width Modulation) driving module and a servo motor, an absolute value encoder is arranged on the servo motor, and all the elements are in signal connection; the output end of the servo motor is rigidly connected with an adjustable guide vane device; the adjustable guide vane device comprises a sleeve, and the sleeve is in interference fit with the inner wall of an air inlet channel of the internal combustion engine. A plurality of guide vanes are arranged in an inner cavity of the sleeve and connected with a rotating shaft penetrating through the wall of the sleeve, and the rotating shaft is rigidly connected to the output end of the servo motor. The front edge radius of the guide vane is larger than the tail edge radius, and the guide vane has a certain torsional angle. The guide vane control system adopts a closed-loop control framework and is matched with the adjustable guide vane device, so that the premixing time is greatly shortened, the vortex of the air inlet channel is enhanced, the combustion efficiency of the internal combustion engine is improved, and meanwhile, the emission of hydrocarbon is reduced.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine intake control and combustion technology, and particularly to an adjustable guide vane control system, control method and internal combustion engine. Background Technology

[0002] With increasingly stringent global carbon reduction regulations, the internal combustion engine industry urgently needs breakthroughs in efficient and clean combustion technologies. Hydrogen internal combustion engines offer zero-carbon fuel as their core advantage, but their performance is highly dependent on the quality of the hydrogen-air mixture. Uneven mixing can lead to excessively rich localized areas, resulting in high NOx levels. X The surge in emissions, coupled with the risk of fire in lean regions, severely restricts the commercial application of hydrogen internal combustion engines.

[0003] Studies have shown that the uniformity of the air-fuel mixture in the combustion chamber is directly controlled by the intake process, with premixing effect and swirl intensity being key factors: the premixing effect determines the initial uniformity of hydrogen and air distribution, affecting flame propagation stability; while the swirl intensity further optimizes the combustion process by enhancing in-cylinder tumble, extending mixing time, and refining fuel particles.

[0004] Existing intake deflector devices for internal combustion engines (such as baffle-type, simple curved blades, and fixed structures) have significant shortcomings in optimizing premixing and vortex flow: baffle-type structures have low adjustment precision, making it difficult to simultaneously meet the requirements of premixing uniformity and vortex intensity; simple curved blades lack scientific aerodynamic profile design, resulting in poor airflow organization and insufficient adaptability to high and low operating conditions; fixed structures completely lack adjustment capabilities and cannot adapt to the intake optimization needs under different operating conditions. These structural defects severely restrict further improvements in the mixture quality and combustion efficiency of hydrogen internal combustion engines. Summary of the Invention

[0005] Therefore, the development of an adjustable guide vane device and guide vane control system, through its unique variable angle of attack mechanism, can precisely control the premixing uniformity and vortex intensity of the intake flow, thereby effectively solving the technical problem of optimizing the mixture quality and combustion organization of hydrogen internal combustion engines under different operating conditions, and providing an innovative solution for improving combustion efficiency and reducing emissions.

[0006] A guide vane control system includes an ECU control unit, a PID controller, a PWM drive module, and a servo motor. The servo motor is equipped with an absolute encoder, and the components are interconnected. An adjustable guide vane device is rigidly connected to the output end of the servo motor. The adjustable guide vane device includes a sleeve that is interference-fitted into the inner wall of the intake manifold of an internal combustion engine. The inner cavity of the sleeve is provided with a plurality of guide vanes, and the guide vanes are connected to a rotating shaft that penetrates the sleeve wall. The rotating shaft is rigidly connected to the output end of the servo motor. The leading edge radius of the guide vane is larger than the trailing edge radius, and it has a certain twist angle.

[0007] This device precisely adjusts the angle of the guide vanes via a servo motor, actively controlling the airflow characteristics within the intake duct. This effectively enhances vortex intensity and optimizes fuel-air premixing uniformity, significantly improving engine combustion efficiency and reducing harmful emissions. A specific twist angle is applied along the blade's spanwise direction, creating an optimized three-dimensional swirling structure as the intake airflow passes over the blade surface. This design allows the leading edge to effectively guide airflow separation, while the tapered trailing edge profile suppresses wake generation. Combined with the twist angle effect, this enhances intake vortex intensity, improves fuel-air mixing uniformity, and reduces flow losses.

[0008] Furthermore, the guide vanes are evenly distributed circumferentially on the inner wall of the sleeve.

[0009] Furthermore, the rotating shaft includes a driving end and a working end, the diameter of the working end is larger than the diameter of the driving end, and the working end is integrally formed with the root of the guide vane.

[0010] This structure, through optimized diameter-to-diameter ratio and integrated connection, significantly improves airflow control accuracy and system durability while ensuring reliable torque transmission, achieving efficient power transmission and aerodynamic control within a compact space.

[0011] Furthermore, the ECU control unit calculates the basic angle and target blade angle of the guide vanes based on data from one or more sensors, including engine speed, intake pressure, temperature, intake flow rate, and air-fuel ratio.

[0012] Furthermore, the PID controller receives the target blade angle calculated by the ECU control unit in real time, compares it with the actual angle fed back by the absolute encoder, and outputs a digital control signal through the PID algorithm.

[0013] Furthermore, the PWM drive module converts the digital control signal output by the PID controller into drive commands for the servo motor.

[0014] Furthermore, the servo motor is a permanent magnet synchronous motor, comprising a rotor, a stator, and a brake; an absolute encoder is provided on the shaft of the servo motor.

[0015] A guide vane control method, applied to the guide vane control system, includes the following steps: The ECU control unit calculates the basic angle and target blade angle of the guide vanes based on data from one or more sensors, including engine speed, intake pressure, temperature, intake flow rate and air-fuel ratio, and transmits the basic angle and target blade angle to the PID controller. The PID controller compares the target blade angle with the actual angle fed back by the encoder and outputs a control quantity. The PWM module converts the control input into a duty cycle to drive the servo motor. The absolute encoder continuously feeds back the actual angle to the PID controller.

[0016] An internal combustion engine includes a cylinder block and a cylinder head, the cylinder head including an intake manifold and a hydrogen injector disposed therein; it also includes a guide vane control system, wherein an adjustable guide vane device in the guide vane control system is installed downstream of the hydrogen injector in the intake manifold.

[0017] The encoder signal is fed back to the PID controller, forming a closed-loop control. The real-time deviation between the encoder feedback signal and the ECU's target angle command is used by the PID controller to accurately calculate the PWM duty cycle correction. Through continuous adjustment, it ensures that the actual position of the guide vanes remains highly consistent with the target command. Combined with the adjustable guide vane device, this significantly shortens the premixing time, enhances the intake swirl, improves the combustion efficiency of the internal combustion engine, and reduces hydrocarbon emissions. Attached Figure Description

[0018] To more clearly illustrate the technical solution of this application, the accompanying drawings required for the embodiments will be briefly described below. It should be noted that the drawings shown in this specification are merely exemplary embodiments. Those skilled in the art can derive other implementation methods based on the shown drawings without creative effort and apply the technical solution of this application to similar scenarios. Unless otherwise stated, the same numbers in the drawings represent the same structures or operating steps.

[0019] Figure 1 This is a cross-sectional view of the internal combustion engine of this application; Figure 2 This is a schematic diagram of the adjustable guide vane device of this application; Figure 3 This is a cross-sectional view of the adjustable guide vane device of this application; Figure 4 This is a schematic diagram of the guide vane control system of this application; Figure 5 This is a flowchart of the guide vane control scheme of this application.

[0020] The symbols for the main components are explained in the table below:

[0021] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0022] To facilitate understanding of the present invention, the following description is provided in conjunction with the accompanying drawings and embodiments. It should be noted that the described embodiments are merely illustrative of the invention and not intended to limit its scope of protection. The present invention can be implemented through various methods; these examples are intended to more comprehensively demonstrate the technical solutions.

[0023] It should be noted that "fixed at" in the text includes both direct and indirect fixation, and "connected" includes both direct and indirect connection. The directional terms "first," "second," etc., are used only for distinction and do not indicate a specific order or importance.

[0024] Unless otherwise stated, the technical terms used herein have their common meanings in the art. "and / or" refers to any combination of related items. The scope of protection of this invention is defined by the claims and is not limited to the embodiments.

[0025] Example 1 Please see Figure 1 Embodiment 1 of the present invention provides an internal combustion engine, which is cylindrical in shape and includes a cylinder block 2 and a cylinder head 3. A piston 1 is provided in the inner cavity of the cylinder block 2, and the piston 1 can reciprocate along the axis of the cylinder block 2. The cylinder head 3 includes an intake passage 4 and an exhaust passage 5, which are connected to the inner cavity of the cylinder block 2. An intake valve 6 is provided at the end of the intake passage 4, and an exhaust valve 7 is provided at the end of the exhaust passage 5.

[0026] The piston 1 adopts a flat-top design, and the cylinder head 3 is a canopy-top design; together with the cylinder block 2, they constitute the combustion chamber in Embodiment 1. This combustion chamber has a compact structure and small surface area, effectively reducing heat loss. Simultaneously, the unique canopy-top design guides the intake airflow to form a strong tumble motion, significantly improving the atomization effect of the air-fuel mixture. The optimized combustion chamber geometry shortens the flame propagation distance, resulting in more complete combustion, which not only improves combustion efficiency but also significantly reduces hydrocarbon emissions. Overall, this combustion chamber design demonstrates excellent performance in both thermodynamics and emission control.

[0027] Furthermore, in this application, the intake manifold 4 and exhaust manifold 5 are symmetrically distributed with respect to the axis of the cylinder head 3, and correspondingly, the intake valve 6 and exhaust valve 7 are also symmetrically distributed with respect to the axis of the cylinder head 3. This structure makes the intake and exhaust flow more balanced, reduces airflow interference, improves charging efficiency, and optimizes the symmetry of the combustion chamber, thereby improving combustion stability.

[0028] Furthermore, in this application, the internal combustion engine adopts an intake manifold injection method, and a hydrogen injector 9 is provided in the intake manifold 4, specifically located upstream of the intake manifold 4. This structure is simple and low in cost, and at the same time, hydrogen and air can be fully premixed before entering the combustion chamber to form a uniform combustible mixture, which is beneficial to improving combustion efficiency and reducing nitrogen oxide emissions.

[0029] Furthermore, the intake duct 4 is also equipped with an adjustable guide vane device 8, which is specifically located downstream of the hydrogen injector 9 and upstream of the intake valve 6. Its core function is to significantly improve the premixing effect of hydrogen and air by optimizing the airflow organization, while guiding the intake air to form a high-intensity vortex. See Embodiment 2 for details, which will not be elaborated here.

[0030] Example 2 Please see Figure 1 , 2 3; Embodiment 2 of the present invention provides an adjustable guide vane device 8, specifically including a sleeve 802, the sleeve 802 being interference-fitted into the inner wall of the air intake 4; the inner cavity of the sleeve 802 is provided with a plurality of guide vanes 801, the guide vanes 801 being connected to a rotating shaft 803 that penetrates the wall of the sleeve 802, forming a rotatable connection structure to ensure that each vane can be adjusted synchronously and precisely.

[0031] Furthermore, the sleeve 802 is cylindrical and adopts a high-strength, lightweight, thin-walled design, with a wall thickness approximately 1 / 16 of the diameter of the air intake 4. The sleeve 802 has four evenly distributed cylindrical holes around its circumference for mounting the rotating shaft 803, ensuring stable adjustment of the guide vanes 801. This design, while ensuring structural rigidity, minimizes the impact on the flow cross-section of the air intake 4.

[0032] Furthermore, the guide vane 801 adopts an aerodynamic airfoil design similar to a turbine blade, with four guide vanes 801 evenly arranged circumferentially within the cavity of the sleeve 802, and the leading edge radius of the guide vane 801... With trailing edge radius The proportional relationship is When the mixed gas flows through the inlet 4, the high-curvature leading edge design effectively suppresses flow separation, while the sharpened trailing edge significantly reduces wake vortex losses. The height H of the guide vane 801 is related to the diameter of the inlet 4. The proportional relationship is The guide vane 801 has a certain twist angle, which causes the airflow flowing over its surface to form a three-dimensional vortex. This structural design allows the leading edge to effectively guide airflow separation, while the tapered trailing edge profile can suppress the generation of wake vortices. Together with the twist angle, they enhance the intensity of the intake vortex, improve the uniformity of fuel-air mixing, and reduce flow losses.

[0033] Furthermore, there are four rotating shafts 803, all of which pass through the pre-drilled cylindrical holes in the sleeve 802 and are connected to the roots of the guide vanes 801 respectively. Each rotating shaft 803 is a segmented cylindrical shaft structure, including a drive end 803a and a working end 803b. The drive end 803a has a standard keyway interface for connection to the transmission system of the servo motor 10. The working end 803b is integrally formed with the root of the guide vane 801. The two shaft diameters are transitioned in a stepped manner through rounded corners to reduce stress concentration. The ratio of the diameter of the drive end 803a to the diameter of the working end 803b is 1.2:1, achieving efficient torque transmission and allowing precise adjustment of the angle of the guide vane 801 under the drive of the servo motor 10.

[0034] By using blade twist angle and airfoil design to generate strong velocity shear and pressure gradients, the airflow is guided to rotate around the cylinder axis (vortex), producing a high-intensity, controllable intake vortex. Simultaneously, the blades shear and turbulent the airflow, breaking up the hydrogen jet and accelerating the diffusion and mixing of the hydrogen-gas mixture. This solves the problems of unstable combustion and high NOx emissions caused by uneven hydrogen-air mixing in hydrogen internal combustion engines.

[0035] In use, the adjustable guide vane device 8 operates on the following principle: Phase 1: Eddy Generation When the working fluid flows through a guide vane with a specific twist angle and airfoil, the pressure distribution on the vane surface forces the airflow to change its path. The twist angle design ensures that a uniform and stable vortex field is generated along the blade span (from root to tip), avoiding flow separation at the tip and guaranteeing vortex intensity. The large leading-edge radius design effectively captures and smoothly guides the incoming flow, reducing flow losses; the sharpened trailing edge minimizes the generation of wake vortices, making the downstream flow field "cleaner," with a clearer vortex structure and slower attenuation.

[0036] Phase Two: Enhanced Premixing (This process occurs simultaneously with Phase One) The guide vane device of this application is located inside the air intake, below the hydrogen injector. The high-speed rotating vortex field itself generates extremely high turbulence intensity. When hydrogen is ejected from the hydrogen injector, it is immediately entrained into this highly turbulent vortex. The powerful shear force and vortex stretching effect rapidly tear apart, entrain, and diffuse the hydrogen jet, enabling the hydrogen and air to achieve a highly uniform mixture at the molecular level in a very short time. This premixing uniformity is an absolute prerequisite for achieving efficient and clean combustion.

[0037] Example 3 Please see Figure 4 and Figure 5The diagrams shown are schematic diagrams of the control method for guide vanes and flowcharts of their control schemes. Embodiment 3 of this invention provides a guide vane control system. The guide vane control system of this invention adopts a closed-loop control architecture: the ECU control unit 13 collects engine operating data in real time, processes it using an algorithm, and generates the target vane angle. The command is sent to the PID controller 12; the PID controller 12 compares and calculates the angle command with the real-time position signal of the blade fed back by the absolute encoder 104, and outputs a precise PWM control signal; the PWM drive module 11 converts the electrical signal into power output to drive the servo motor 10 to run; the motor output shaft is rigidly connected to the rotating shaft 803 through a coupling, which drives the guide vane 801 to rotate precisely under the support of the sleeve 803.

[0038] Furthermore, the ECU control unit 13, as the core of the system, collects engine speed data in real time. N Intake pressure P ,temperature T Intake flow rate Q and air-fuel ratio λ Key parameters such as the basic angle are calculated using four-dimensional dynamic pulse spectrum interpolation. θ 0, and apply multi-parameter dynamic compensation to calculate the final target blade angle. θ The calculation results are then transmitted to the PID controller 12 via the CAN bus. The relevant calculation formulas are as follows:

[0039]

[0040] In the formula, Based on rotational speed N Load factor Intake flow rate Q air-fuel ratio λ Four-dimensional pulse spectrum interpolation. These are compensation coefficients; different subscripts represent different types of compensation coefficients. (Subscript) ref This represents the value under standard operating conditions, specifically... T ref Standard temperature P ref For standard pressure, Q ref To calibrate the flow rate, λ ref This is the theoretical air-fuel ratio.

[0041] Furthermore, the PID controller 12 is an intelligent control module with dynamic adjustment function, which achieves high-precision angle tracking through the coordinated operation of proportional-integral-derivative three-stage calculations. This controller receives the target blade angle transmitted in real time by the ECU control unit 13 via the CAN bus. θ and the actual angle fed back by the absolute encoder 104 θ f The comparison is performed to generate a PWM control signal to drive the servo motor 10. The control algorithm is expressed as follows:

[0042] In the formula, u(t) It is the digital control signal ultimately output by the PID algorithm, including the error signal. proportionality coefficient K p Fast response angle deviation, integral coefficient K i Eliminating steady-state error, differential coefficients K d Suppress overshoot.

[0043] Furthermore, the PWM drive module 11 is a high-precision power conversion device, whose core function is to convert the digital control signal output by the PID controller 12 into a digital control signal. u(t) This is converted into drive commands for servo motor 10. The module receives PID calculation results in real time and generates a high-frequency PWM wave using pulse width modulation technology, with a duty cycle... D(t) With control quantity u(t) The conversion relationship is as follows:

[0044] In the formula, u min and u max These correspond to the minimum and maximum limit values ​​of the PID output, respectively. This design ensures a fast response from the servo motor while improving the accuracy of motor speed control, meeting the requirements for precise blade angle positioning.

[0045] Furthermore, the servo motor 10 is a high-dynamic-response actuator, employing a permanent magnet synchronous motor structure, comprising a rotor 101, a stator 102, and an integrated brake 103. This motor is directly connected to the guide vane shaft 803 via a coupling, transmitting the duty cycle signal output by the PWM drive module 11. D(t) This is converted into precise electromagnetic torque. An absolute encoder 104 is installed at the motor tail to provide real-time feedback on the real-time angle of the guide vanes. θ fThe PID controller then forms a fully closed-loop control system. Simultaneously, the integrated brake 103 instantly locks the shaft upon power failure to prevent inertial drift. This design features closed-loop control, rapid response, and power-off self-locking.

[0046] Furthermore, the absolute encoder 104 is a high-precision angle detection device that adopts a photoelectric multi-turn encoding structure (17-bit resolution, corresponding to 0.002° angle accuracy). It is directly installed on the output shaft at the tail of the servo motor 10 and indirectly obtains the real-time angle of the guide vane 801 by detecting the magnetic pole position of the motor rotor 101. θ f The absolute encoder 104 feeds back angle data to the PID controller 12 via a high-speed SPI interface, and its signal conversion formula is as follows:

[0047] In the formula, This is the encoder's raw count value, representing the encoder's angle relative to the target blade angle of the ECU. θ Real-time deviation value It directly participates in PID calculations, enabling the system to achieve precise positioning.

[0048] In summary, this invention provides an adjustable guide vane device and a variable-angle guide vane control system, as well as an internal combustion engine including the adjustable guide vane device. The adjustable guide vane device includes turbine-inspired adjustable vanes, a segmented shaft, and a high-strength sleeve. Precise adjustment of the vane angle is achieved through a servo motor drive. The control system consists of an ECU unit, a PID controller, a PWM drive module, and an absolute encoder. The ECU calculates the target angle based on engine speed, intake parameters, and air-fuel ratio using four-dimensional pulse spectrum interpolation. The PID controller implements closed-loop control based on encoder feedback, and the PWM module converts the control signal into motor drive commands. This device is installed downstream of the hydrogen injector in the intake manifold, working in conjunction with the dome-shaped combustion chamber. This significantly shortens the premixing time and enhances the intake manifold vortex, interacting with the cylinder tumble flow to improve the combustion efficiency of the internal combustion engine while reducing hydrocarbon emissions.

[0049] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A guide vane control system, characterized in that: The system includes an ECU control unit (13), a PID controller (12), a PWM drive module (11), and a servo motor (10). The servo motor (10) is equipped with an absolute encoder (104), and the above components are connected by signals. The output end of the servo motor (10) is rigidly connected to an adjustable guide vane device. The adjustable guide vane device includes a sleeve (802), which is interference-fitted to the inner wall of the intake manifold (4) of the internal combustion engine. The inner cavity of the sleeve (802) is provided with several guide vanes (801), and the guide vanes (801) are connected to a rotating shaft (803) that penetrates the wall of the sleeve (802). The rotating shaft (803) is rigidly connected to the output end of the servo motor (10). The leading edge radius of the guide vane (801) is greater than the trailing edge radius, and it has a certain twist angle.

2. The guide vane control system according to claim 1, characterized in that: The guide vanes (801) are evenly distributed circumferentially on the inner wall of the sleeve (802).

3. The guide vane control system according to claim 1, characterized in that: The rotating shaft (803) includes a driving end (803a) and a working end (803b). The diameter of the working end (803b) is larger than the diameter of the driving end (803a). The working end (803b) is integrally formed with the root of the guide vane (801).

4. The guide vane control system according to claim 1, characterized in that: The ECU control unit (13) calculates the basic angle and target blade angle of the guide vane (801) based on data from one or more sensors, including engine speed, intake pressure, temperature, intake flow rate and air-fuel ratio.

5. The guide vane control system according to claim 4, characterized in that: The PID controller (12) receives the target blade angle calculated by the ECU control unit (13) in real time and compares it with the actual angle fed back by the absolute encoder (104), and outputs a digital control signal through the PID algorithm.

6. The guide vane control system according to claim 5, characterized in that: The PWM drive module (11) converts the digital control signal output by the PID controller (12) into a drive command for the servo motor (10).

7. The guide vane control system according to claim 5, characterized in that: The servo motor (10) is a permanent magnet synchronous motor, which includes a rotor (101), a stator (102) and a brake (103); an absolute encoder (104) is provided on the shaft of the servo motor (10).

8. A guide vane control method, applied to the guide vane control system according to any one of claims 1-7, characterized in that: Includes the following steps: The ECU control unit (13) calculates the basic angle and target blade angle of the guide vane (801) based on data from one or more sensors, including engine speed, intake pressure, temperature, intake flow rate and air-fuel ratio, and transmits the basic angle and target blade angle to the PID controller (12). The PID controller (12) compares the target blade angle with the actual angle fed back by the encoder (104) and outputs a control quantity; The PWM module (11) converts the control quantity into a generated duty cycle to drive the servo motor (10). The absolute encoder (104) continuously feeds back the actual angle to the PID controller (12).

9. An internal combustion engine, characterized in that: It includes a cylinder block (2) and a cylinder head (3), the cylinder head (3) including an intake passage (4) and a hydrogen injector (9) provided in the intake passage (4); it also includes a guide vane control system as described in any one of claims 1-7, wherein the adjustable guide vane device in the guide vane control system is installed downstream of the hydrogen injector (9) in the intake passage (4).

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