Intelligent air inflow adjusting system suitable for opposed-piston two-stroke hydrogen engine and control method

Abstract

The invention belongs to the technical field of engines, and particularly relates to an intelligent air inflow adjusting system suitable for an opposed-piston two-stroke hydrogen engine and a control method. The first transition mechanism is arranged at the inlet end of the air inlet channel inlet; the air inlet pipes fixedly communicate with the outlet end of the air inlet channel inlet, and the air inlet pipes are arranged in an array mode in the circumferential direction; the second transition mechanism is arranged at the communicating end of the air inlet pipe and the inlet of the air inlet channel; the flow guide mechanism is arranged between the air inlet pipe and the engine cylinder; and the section valve groups are in one-to-one correspondence with the air inlet pipes and are movably arranged at the outlet ends of the air inlet pipes. Through optimal design of structural parameters of the air channel and the flow guide plate, high-flow-speed and low-resistance stable flow in the air inlet channel is achieved; through flexible control of the air inlet turning plate, accurate and efficient control over the air inlet amount, the air flow speed and the air flow direction is achieved.

Description

Technical Field

[0001] This invention belongs to the field of engine technology, and in particular relates to an intelligent intake volume adjustment system and control method suitable for opposed piston two-stroke hydrogen engines. Background Technology

[0002] Opposed-piston two-stroke engines eliminate the cylinder head and complex valve train (such as camshafts and valves) of traditional four-stroke engines, resulting in a compact structure and high power density. However, the control of intake air volume in opposed-piston two-stroke engines heavily relies on the geometry of the intake port. As the only path that guides and controls the intake working fluid into the cylinder, the structure of the intake port directly determines the amount of intake air, the flow rate, and the uniformity of airflow distribution, making it a core component affecting engine scavenging efficiency and final performance.

[0003] Existing technologies for intake volume control in opposed-piston two-stroke engines have significant shortcomings: 1. Lack of an effective intake volume control mechanism. Traditional intake ports are mostly designed with fixed cross-sections, making it impossible to dynamically optimize intake flow and velocity based on engine operating conditions (such as speed and load). This results in insufficient intake kinetic energy and poor scavenging effect under partial load; at high loads, flow resistance becomes a bottleneck, limiting maximum power output. 2. The intake port structure itself is not conducive to precise control. The connections between the intake port and the intake port body, and between the intake port and the cylinder liner, often use right angles or abrupt changes in cross-section, which easily induces airflow separation and turbulence, causing significant pressure loss. This not only makes the actual intake volume far lower than the theoretical value, but also limits the effectiveness of any active intake volume control strategy based on the engine electronic control unit due to the poor performance of the underlying flow channels. 3. Existing designs do not consider the active guidance and control of the intake working fluid flow direction. The airflow direction is turbulent when entering the cylinder, resulting in poor controllability of the scavenging process, excessive residual exhaust gas in the cylinder, and further deterioration of the engine's thermal efficiency.

[0004] Therefore, it is necessary to design an intelligent intake volume regulation system and control method suitable for opposed piston two-stroke hydrogen engines to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide an intelligent intake volume adjustment system and control method suitable for opposed piston two-stroke hydrogen engines to solve the above-mentioned problems. By optimizing the design of the air passage and guide vane structural parameters, high flow velocity and low resistance stable flow are achieved in the intake passage; and by flexibly controlling the intake flap, precise and efficient control of intake volume, airflow velocity and airflow direction is achieved.

[0006] To achieve the above objectives, the present invention provides the following solution: an intelligent intake volume adjustment system suitable for a opposed piston two-stroke hydrogen engine, comprising: an intake duct body having an intake duct inlet inside; a first transition mechanism disposed at the inlet end of the intake duct inlet, the inlet of the first transition mechanism being connected to the inlet end of the intake duct inlet, the cross-sectional area of ​​the inlet end of the intake duct inlet gradually increasing towards the outlet end; multiple intake pipes fixedly connected to the outlet end of the intake duct inlet, the multiple intake pipes being arranged in an array along the circumferential direction; a second transition mechanism disposed at the connection end between the intake pipe and the intake duct inlet; a flow guiding mechanism disposed between the intake pipe and the engine cylinder, the flow guiding mechanism being used to guide airflow uniformly into the engine cylinder; multiple cross-sectional valve groups, the cross-sectional valve groups corresponding one-to-one with the intake pipe and movably disposed at the outlet end of the intake pipe, the cross-sectional valve groups being used to adjust the effective flow cross-sectional area at the outlet end of the intake pipe; and an engine electronic control unit connected to the cross-sectional valve groups.

[0007] According to the present invention, an intelligent intake volume adjustment system for a two-stroke hydrogen engine with opposed pistons is provided, wherein the first transition mechanism includes an arc transition section, which is disposed on the inner side wall of the inlet end of the intake manifold.

[0008] According to the present invention, an intelligent intake volume adjustment system for a two-stroke hydrogen engine with opposed pistons is provided, wherein the radius of the arc transition section is 60mm-65mm and the transition length of the arc transition section is 30mm.

[0009] According to the present invention, an intelligent air intake adjustment system for a two-stroke hydrogen engine with opposed pistons is provided, wherein the second transition mechanism includes an intake pipe transition section, which is disposed at the connection end between the intake pipe and the intake duct inlet.

[0010] According to the present invention, an intelligent intake volume adjustment system for a two-stroke hydrogen engine with opposed pistons is provided, wherein the intake pipe transition section is inclined, the inclination angle of the intake pipe transition section is 10°-15°, and the transition length of the intake pipe transition section is 10mm.

[0011] According to the present invention, an intelligent intake volume adjustment system for a two-stroke hydrogen engine with opposed pistons is provided, wherein the flow guiding mechanism includes an arc-shaped flow guiding rib, and the arc-shaped flow guiding rib is disposed between the intake pipe and the engine cylinder.

[0012] According to the present invention, an intelligent intake volume adjustment system for a two-stroke hydrogen engine with opposed pistons is provided, wherein the radius of the arc-shaped guide rib is 10mm-15mm.

[0013] According to the present invention, an intelligent intake volume adjustment system for a two-stroke hydrogen engine with opposed pistons is provided. The cross-section valve group includes a valve plate, which is rotatably connected to the inside of the outlet end of the intake pipe via a valve stem. One end of the valve stem is provided with a positioning pin, and the other end of the valve stem is provided with a rotary drive unit.

[0014] According to the present invention, an intelligent intake volume adjustment system for a opposed piston two-stroke hydrogen engine is provided, wherein the rotary drive unit includes a drive rocker arm, one end of which is fixedly connected to the valve stem, and the other end of which is provided with a rotary actuator.

[0015] A control method for an intelligent intake volume adjustment system suitable for a opposed-piston two-stroke hydrogen engine includes the following steps: The engine electronic control unit (ECU) performs a self-test to confirm power-on. Upon power-up, the ECU acquires real-time engine operating condition information via its analog-to-digital conversion channel and communication bus. This real-time operating condition information includes at least engine speed data, intake air velocity data, and intake air flow rate data. The ECU verifies the validity of this real-time operating condition information. If the information is invalid, the ECU controls the cross-sectional valve assembly to a fully open safe position. If the information is valid, the ECU begins to determine the engine's operating status. If the engine speed is higher than a preset threshold, the ECU determines that the engine is in normal operating condition. The ECU acquires intake manifold flow rate data. Based on a preset relationship between the acquired intake manifold flow rate data and the target flow area, the ECU obtains target flow area data and controls the opening degree of the cross-sectional valve assembly based on the obtained target flow area data.

[0016] Compared with the prior art, the present invention has the following advantages and technical effects: 1. It realizes active and precise control of intake volume: Through the variable section valve group, the intake cross-sectional area can be steplessly adjusted according to the real-time operating conditions of the engine (speed, load), which fundamentally solves the pain point that the fixed section air passage cannot adapt to the full operating conditions. The control response speed is fast and the precision is high.

[0017] 2. Significantly Improved Performance Across All Operating Conditions: Low-to-medium speed conditions: By reducing the cross-section and increasing the flow velocity, the in-cylinder airflow intensity (turbulent kinetic energy) is enhanced, improving combustion speed and increasing engine thermal efficiency. High-speed conditions: With the cross-section valve assembly fully open, the ultra-low flow resistance of the basic intake passages is fully utilized, increasing the intake airflow and ensuring high engine power output. It also improves intake uniformity.

[0018] 3. Improved scavenging efficiency and emissions: Combined with the directional guidance of the guide ribs and the controllable airflow brought by the variable cross section, the scavenging process is more thorough, the in-cylinder exhaust gas coefficient is reduced, and it helps to achieve completely clean combustion of hydrogen fuel.

[0019] 4. Compact structure and high reliability: The cross-section valve group is directly integrated into the optimized air passage body, without the need for major modifications to the main engine structure. The actuation mechanism is simple and reliable, and it is easy to implement on existing engine platforms. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the airway body and the air intake pipe of the present invention.

[0022] Figure 2 This is a cross-sectional view of the airway body and the air intake pipe of the present invention.

[0023] Figure 3 This is a schematic diagram of the cross-section valve assembly of the present invention.

[0024] Figure 4 This is a schematic diagram of the system of the present invention.

[0025] Figure 5 This is the control flowchart of the present invention.

[0026] Figure 6 This is a comparison chart of the flow rates of the embodiment and the prototype of the present invention.

[0027] Figure 7 This is a comparison diagram of the flow rate of the embodiment and the prototype of the present invention.

[0028] The components are as follows: 1. Intake duct inlet; 2. Intake duct body; 3. Intake pipe; 4. Arc transition section; 5. Intake pipe transition section; 6. Arc-shaped guide rib; 7. Section valve assembly; 7a. Valve plate; 7b. Valve stem; 7c. Positioning pin; 7d. Drive rocker arm; 7e. Rotary actuator; 8. Intake main pipe; 9. First intake branch pipe; 10. Second intake branch pipe; 11. Control unit; 12. Air filter; 13. Throttle valve; 14. First intake status sensor; 16. Second intake status sensor; 17. First drive motor; 19. Third intake status sensor; 20. Second drive motor; 21. Engine cylinder. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Reference Figures 1 to 7 As shown, the present invention provides an intelligent air intake adjustment system suitable for opposed piston two-stroke hydrogen engines, including: an air intake body 2, with an air intake inlet 1 inside; the air intake inlet 1 and the air intake body 2 are designed with the same width, and the inlet edge is rounded to avoid airflow disturbance caused by sharp edges; the air intake body 2 adopts a gradually changing cross-sectional structure, and the cross-sectional area increases linearly from the inlet to the connection of the air intake pipe 3.

[0032] The air intake inlet 1 is 173mm wide and 38mm high; the air intake body 2 is 120mm long and its cross-section gradually changes from 173mm×38mm to 173mm×46mm.

[0033] The inlet area is maximized to reduce contraction resistance, and the gradient cross section is adapted to the acceleration characteristics of hydrogen flow to avoid pressure loss caused by sudden velocity changes, while improving the flow storage and buffering capacity.

[0034] The first transition mechanism is located at the inlet end of the air intake duct 1. The first transition mechanism is used to make the airflow flow along a streamlined path. Multiple air intake pipes 3 are fixedly connected to the outlet end of the air intake duct 1. The multiple air intake pipes 3 are arranged in an array along the circumferential direction. The cross-sectional size of the air intake pipe 3 is 17mm×14mm. The inner wall of the air intake pipe 3 is polished and the inner wall roughness Ra≤0.8μm. This achieves a smooth and gradual change in the cross-section of the air duct, further optimizes the airflow direction, reduces energy loss at the connection, and the polished inner wall reduces the frictional resistance between the airflow and the wall surface.

[0035] The second transition mechanism is located at the connection end between the intake pipe 3 and the intake duct inlet 1. The second transition mechanism is used to reduce energy loss. The flow guiding mechanism is located between the intake pipe 3 and the engine cylinder 21. The flow guiding mechanism is used to guide the airflow to enter the engine cylinder 21 evenly. Multiple cross-section valve groups 7 are corresponding one-to-one with the intake pipe 3 and are movably installed at the outlet end of the intake pipe 3. The cross-section valve groups 7 are used to adjust the effective flow cross-sectional area at the outlet end of the intake pipe 3.

[0036] Furthermore, the first transition mechanism includes an arc transition section 4, which is disposed on the inner side wall of the inlet end of the air intake duct 1.

[0037] Furthermore, the radius of the arc transition section 4 is 60mm-65mm, and the transition length of the arc transition section 4 is 30mm.

[0038] The radius of the arc transition section 4 is preferably 60.25mm, which completely eliminates the airflow separation phenomenon caused by the traditional right-angle transition, so that the airflow flows smoothly along the streamlined path and reduces energy loss.

[0039] Furthermore, the second transition mechanism includes an intake pipe transition section 5, which is located at the connection end between the intake pipe 3 and the intake duct inlet 1.

[0040] Furthermore, the intake pipe transition section 5 is inclined, with an inclination angle of 10°-15° and a transition length of 10mm.

[0041] The preferred inclination angle of the intake manifold transition section 5 is 13°.

[0042] Furthermore, the airflow guiding mechanism includes an arc-shaped airflow guide rib 6, which is disposed between the intake pipe 3 and the engine cylinder 21.

[0043] Furthermore, the radius of the arc-shaped guide rib 6 is 10mm-15mm.

[0044] The radius of the arc-shaped guide rib 6 is preferably 12mm to guide the airflow direction, so that the airflow enters the cylinder evenly, reduce the resistance caused by airflow turbulence, and enhance the scavenging effect.

[0045] Furthermore, the cross-section valve assembly 7 includes a valve plate 7a, which is rotatably connected to the inside of the outlet end of the intake pipe 3 via a valve stem 7b. One end of the valve stem 7b is provided with a positioning pin 7c, and the other end of the valve stem 7b is provided with a rotary drive unit.

[0046] Furthermore, the rotary drive unit includes a drive rocker arm 7d, one end of which is fixedly connected to the valve stem 7b, and the other end of which is provided with a rotary actuator 7e.

[0047] The valve stem 7b passes through a hole in the intake pipe 3, causing the valve plate 7a to approach the upper inner wall of the intake pipe 3. The valve stem 7b can rotate, thereby rotating the valve plate 7a to cover the intake pipe 3, thus changing the flow area. The valve plate 7a can rotate up to 35°, covering approximately 80% of the flow width of the intake pipe 3. The valve plate 7a is made of thin-walled stainless steel with a thickness of 1mm. The stroke of the valve stem 7b is ±10mm. By adjusting the rotation angle of the valve plate 7a, the actual effective flow cross-sectional area of ​​the intake pipe 3 can be steplessly adjusted, thereby achieving active control of the intake flow rate and velocity.

[0048] One end of the valve stem 7b is fixed with a locating pin 7c, and the other end is connected to a drive rocker arm 7d. A rotary actuator 7e is mounted on the end of the drive rocker arm 7d furthest from the valve stem 7b. The rotary actuator 7e is externally connected to a control unit (not shown in the figure). The control unit receives signals from sensors such as engine speed and load, and outputs commands to drive the rotary actuator 7e to rotate. This converts the electronic control commands into precise mechanical movement of the cross-sectional valve assembly 7, forming the execution link of closed-loop control.

[0049] The control unit 11 in the system receives and calculates various information and issues instructions; the air filter 12 filters the air entering the system to prevent dust and other impurities in the air from damaging related components; the throttle valve 13 adjusts the engine load by changing its opening; the first intake status sensor 14 measures and collects the intake status of the intake system as a basis for calculating the engine operating condition; the section valve assembly 7 is controlled by the first drive motor 17 and changes the flow area of ​​the first intake manifold 9 by rotating; the second intake status sensor 16 measures and collects the intake status of the first intake manifold 9 as a basis for the control unit 11 to calculate the rotation angle of the section valve assembly 7; the first drive motor 17 receives instructions from the control unit 11 and controls the rotation angle of the section valve assembly 7; the section valve assembly 7 is controlled by the second drive motor 20 and changes the flow area of ​​the second intake manifold 10 by rotating; the third intake status sensor 19 measures and collects the intake status of the second intake manifold 10 as a basis for the control unit 11 to calculate the rotation angle of the section valve assembly 7. The second drive motor 20 receives instructions from the control unit 11 and controls the rotation angle of the section valve group 7.

[0050] Example 1: A control method for an intelligent intake volume regulation system suitable for a opposed piston two-stroke hydrogen engine, comprising the following steps.

[0051] Step 101: System startup and self-test.

[0052] The control process begins. The engine electronic control unit (ECU) first performs a self-test to confirm that it has completed power-on initialization and that its internal voltage is stable.

[0053] Step 102: Power status determination.

[0054] The ECU determines whether it is in a valid "power-on" working state.

[0055] If the judgment is "No": the ECU will enter a safe state, reset all control variables and flags (such as target angle, enable flag, etc.), and end the current control cycle, waiting for the next activation.

[0056] If the result is "yes": the process enters the data collection stage.

[0057] Step 103: Real-time operating condition information collection.

[0058] The ECU collects and updates the following sensor signals in real time through its analog-to-digital conversion channel and communication bus: Engine speed: from the crankshaft position sensor.

[0059] Engine load signal: from the accelerator pedal position sensor or the relative load value calculated by the intake air volume / torque model.

[0060] Key intake parameters: Intake pressure and intake temperature are collected before and after the throttle valve 13, and downstream of the first intake manifold 9 and the second intake manifold 10, via the first intake status sensor 14, the second intake status sensor 16, and the third intake status sensor 19. Additionally, if the system is equipped with a hot-wire or hot-film air flow meter, the intake mass flow rate signal is collected simultaneously.

[0061] Step 104: Signal validity diagnosis.

[0062] The diagnostic module built into the ECU verifies the validity of all signals acquired in step 103, including checking whether the signal values ​​are within a physically reasonable range, whether there is a short circuit to the power supply or to ground, and whether the signal has timed out and not been updated.

[0063] If any critical signal is deemed "invalid," the ECU will employ a fail-safe strategy, setting the "operation enable flag" of the drive motor to "disable." Subsequently, the ECU will output control commands, regardless of the current command, to force the first drive motor 17 and the second drive motor 20 to operate, causing the two cross-sectional valve assemblies 7 to rotate to a predefined safe fully open position. This maximizes the flow area, minimizes intake resistance, ensures basic engine operation, and ends the current cycle.

[0064] If all signals are deemed "valid", the process proceeds to the next judgment step.

[0065] Step 105: Determine the engine operating status.

[0066] The ECU determines whether the engine is in an "operating state" that requires precise control of the intake air volume based on the collected engine speed.

[0067] The engine speed is compared with a preset minimum effective speed threshold (e.g., 800 rpm, above idle speed).

[0068] If the engine speed is below this threshold: the ECU determines that the engine is in a starting, shut-off, or very low-speed state, and no variable intake adjustment is required. The system executes a fail-safe strategy similar to the signal invalidation time, prohibiting the drive motor from operating and placing the valve plate in the safe fully open position.

[0069] If the engine speed is higher than or equal to this threshold, the ECU determines that the engine is operating normally. At this time, the system sets the "operation enable flag" of the drive motor to "allow," preparing to execute precise control.

[0070] Step 106: Core parameter calculation and target opening decision. The target opening of valve plate 7a is calculated using a method based on a fluid network model, which is achieved by jointly solving the following three formulas: using the flow distribution formula. The target flow rate of each branch is determined based on the total target flow rate Q0. .

[0071] in: —Flow rate after adjustment by the valve plate of the i-th intake manifold; —Total flow rate after main pipeline adjustment; —The fluid resistance after adjustment by the valve plate of the kth intake manifold.

[0072] Using the impedance-area relationship formula Convert the target traffic demand into the required target circulation area. .

[0073] in: —The fixed impedance coefficient of the k-th intake manifold; —The cross-sectional area of ​​the flow after adjustment of the valve plate of the kth intake manifold; —Initial state, the inlet and outlet pressure difference of all intake manifolds; —The flow cross-sectional area of ​​the kth intake branch pipe in its initial state; —The original flow rate before adjustment of the valve plate of the kth intake manifold.

[0074] Using geometric formulas Finally, the target area was calculated. The required target rotation angle β of the valve disc.

[0075] This step is the core of the control algorithm. The ECU performs the following calculations in sequence: Calculate the target total flow rate Q. 0target The ECU, based on the current engine speed (Ne) and load rate, queries the performance calibration MAP to obtain the target total intake air mass flow rate required for optimal combustion under the current operating conditions, and converts it into the target volumetric flow rate Q under standard conditions. 0target .

[0076] Calculate the target flow rate Q for each branch pipe itarget Based on engine balance control requirements, the ECU allocates target flow rates to each intake manifold. Typically, the target flow rate for each manifold is set to be equal, i.e., Q. 1target =Q 2target =...=Q 0target / n (n is the number of intake manifold groups).

[0077] Inverse calculation of the required fluid resistance Z itarget To achieve the set flow distribution, the ECU needs to calculate the fluid resistance that each branch pipe should reach.

[0078] Under the target conditions, the target flow rate Q of all intake manifolds itarget and the target flow rate Q of the main pipeline 0target Known.

[0079] The ECU calculates a set of target fluid impedances Z using an iterative algorithm. 1target Z 2target ..., so that when these are substituted into the target flow formula, the calculated distributed flow is equal to the target flow of each branch pipe.

[0080] Convert the target impedance to the target flow area A. itarget : Obtain Z itarget Then, the ECU uses a modified version of the impedance-area relationship formula: , where K k It is the fixed impedance coefficient of the k-th intake manifold, which is obtained through calibration during system initialization.

[0081] Therefore, the ECU calculates the target flow cross-sectional area A required for each intake manifold valve plate to achieve the target flow distribution. itarget .

[0082] Convert the target flow cross-sectional area into the target rotation angle β of the valve plate. itarget Finally, the ECU uses the inverse operation of the geometric relationship formula: Solve for the valve plate rotation angle.

[0083] In the formula, the branch pipe width w, height h, valve stem geometric parameters R and α are all known fixed mechanical parameters.

[0084] The ECU will use the A obtained in the previous step itarget Substituting into the formula, the corresponding valve plate target rotation angle β is calculated. itarget This angle represents the final position command that the drive motor needs to execute.

[0085] Step 107: Actuator drive and position closed loop.

[0086] The ECU will calculate β itarget The signal is sent to the corresponding drive motor. The drive motor rotates the valve plate, and the position sensor provides real-time feedback of the actual angle β. itarget This forms a closed-loop control until the error between the actual angle and the target angle enters the allowable tolerance zone. The anti-shake logic (minimum state hold time) also takes effect.

[0087] Step 108: Execute repeatedly.

[0088] After the control cycle ends, the process returns to step 103 to begin a new round of sensing, calculation, and adjustment.

[0089] Example 2: Intelligent control process with feedforward compensation. Based on Example 1, this example introduces a more advanced feedforward control to improve the response speed under transient conditions.

[0090] Steps 201 to S205: Same as in Example 1, complete all pre-checks and signal acquisition.

[0091] Step 206: Calculate the feedforward opening based on the operating condition prediction.

[0092] While performing detailed calculations in step 106, the ECU executes a fast feedforward channel in parallel: based on the current driver operation (such as the rate of change of the accelerator pedal) and engine status, the ECU predicts the engine speed Ne one control cycle from now. future and load future .

[0093] Using a simplified, pre-trained neural network or a high-dimensional MAP graph, directly from (Ne future and Load future This maps to the predicted recommended opening β of each intake manifold valve. ff This mapping relationship was derived during bench calibration by fitting a large amount of data to complete fluid dynamics calculations (i.e., all formulas in step 106), essentially serving as a "computational shortcut".

[0094] Step 207: Feedforward-feedback fusion.

[0095] The ECU will output the fast suggested opening β from the feedforward channel. ff The precise target opening β calculated based on the current actual flow rate by the feedback channel (step 106) fb Perform weighted fusion: β target =γ*β ff +(1-γ)*β fb The weight γ is set to a larger value under transient engine conditions (such as rapid acceleration) to take advantage of the fast feedforward response; and a smaller value under steady-state conditions to ensure accuracy through feedback.

[0096] Step 208: Instruction execution and loop closure.

[0097] ECU with fused β target As the final command, the drive motor executes it. The subsequent position closed loop is the same as in Example 1.

[0098] Specific implementation: A digital three-dimensional model was established based on a single-cylinder opposed piston two-stroke hydrogen engine, and digital simulation was performed. The engine parameters are as follows: cylinder diameter 74.5mm, stroke 86mm, connecting rod length 169mm, speed 2000r / min, and calculated operating conditions: intake pressure 104kpa, exhaust pressure 100kpa.

[0099] The specific parameters of the air duct structure are as follows: Inlet 1: width 173mm, height 38mm, designed with the same width as the air duct body 2, with rounded corners at the inlet edge (radius 2mm); Air duct body 2: length 120mm, cross-section gradually changes from 173mm×38mm at the inlet 1 to 173mm×46mm at the connection with the intake pipe 3; Arc transition section 4: arc radius selection range is 60mm-65mm, transition length connecting the inlet 1 and the air duct body 2 is 30mm, ensuring a smooth transition without steps; Intake pipe 3: cross-section length 17mm, width 14mm, inner wall polished (roughness Ra≤0.8μm); Intake pipe transition section 5: tilt angle selection range is 10°-15°, transition length 10mm; Arc-shaped guide rib 6: arc radius selection range is 10mm-15mm.

[0100] Under the same initial conditions, simulation results show that this structure can significantly increase the intake airflow.

[0101] 1. Traffic comparison: such as Figure 6 As shown, compared with the traditional intake duct structure, the flow rate of the present invention is significantly higher throughout the entire intake stroke. When the crankshaft angle is 180°CA ATDC, the flow rate reaches 0.11kg / s, which is 15.8% higher than the traditional structure (0.095kg / s).

[0102] 2. Flow rate comparison: such as Figure 7 As shown, the average airflow velocity of the present invention reaches 28 m / s, which is 21.7% higher than that of the traditional structure (23 m / s), and the velocity fluctuation is smaller, resulting in better airflow stability.

[0103] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0104] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope of the present invention.

Claims

1. An intelligent air intake quantity adjustment system for a hydrogen engine with opposed pistons, characterized in that, The utility model relates to an air inlet passage of engine, including: Air passage body (2) inside is provided with air inlet passage entrance (1); First transition mechanism is arranged in the entrance of air inlet passage entrance (1), the entrance of first transition mechanism is connected with the entrance of air inlet passage entrance (1), and the cross section area of the entrance of air inlet passage entrance (1) gradually expands towards the exit end; Multiple air inlet pipes (3) are fixedly connected in the exit end of air inlet passage entrance (1), and multiple air inlet pipes (3) are arranged in the circumferential direction; Second transition mechanism is arranged in the communication end of air inlet pipe (3) and air inlet passage entrance (1); Flow guide mechanism is arranged between air inlet pipe (3) and engine cylinder (21), and the flow guide mechanism is used for guiding airflow to enter into engine cylinder (21) uniformly; Multiple cross section valve groups (7) are correspondingly arranged in the exit end of air inlet pipe (3), and the cross section valve group (7) is used for adjusting the effective flow cross section area of the exit end of air inlet pipe (3); Engine electronic control unit is connected with cross section valve group (7).

2. The intelligent air charge mass regulating system for a hydrogen opposed-piston two-stroke engine according to claim 1, characterized in that, The first transition mechanism includes a circular arc transition section (4) arranged on the inner side wall of the entrance end of the air inlet passage entrance (1).

3. The intelligent air charge mass regulating system for use in an opposed-piston two-stroke hydrogen engine according to claim 2, characterized in that, The circular arc radius of the circular arc transition section (4) is 60-65 mm, and the transition length of the circular arc transition section (4) is 30 mm.

4. The intelligent air charge mass regulating system for use in an opposed-piston two-stroke hydrogen engine according to claim 1, characterized in that, The second transition mechanism includes an air inlet pipe transition section (5) arranged at the communication end of the air inlet pipe (3) and the air inlet passage entrance (1).

5. The intelligent air charge mass regulating system for use in an opposed-piston two-stroke hydrogen engine according to claim 4, characterized in that, The air inlet pipe transition section (5) is arranged at an inclination, the inclination angle of the air inlet pipe transition section (5) is 10-15°, and the transition length of the air inlet pipe transition section (5) is 10 mm.

6. The intelligent air charge management system for use in an opposed-piston, two-stroke hydrogen engine of claim 1, wherein The flow guide mechanism includes a circular arc flow guide rib (6) arranged between the air inlet pipe (3) and the engine cylinder (21).

7. The intelligent air charge mass regulating system for use in an opposed-piston two-stroke hydrogen engine according to claim 6, characterized in that, The circular arc radius of the circular arc flow guide rib (6) is 10-15 mm.

8. The intelligent air charge management system for use in an opposed-piston, two-stroke hydrogen engine of claim 1, wherein, The cross section valve group (7) includes a valve plate (7a) rotatably connected to the inside of the exit end of the air inlet pipe (3) through a valve rod (7b), one end of the valve rod (7b) is provided with a positioning pin (7c), and the other end of the valve rod (7b) is provided with a rotary drive part.

9. The intelligent air charge mass regulating system for use in an opposed-piston two-stroke hydrogen engine according to claim 8, characterized in that, The rotary drive part includes a drive rocker (7d) fixedly connected to one end of the valve rod (7b), and the other end of the drive rocker (7d) is provided with a rotary actuator (7e).

10. A control method for the intelligent air charge adjustment system of a hydrogen engine with opposed pistons according to any one of claims 1-9, characterized in that, The method includes the following steps: Through the self-checking of the engine electronic control unit, when the power is turned on, the engine electronic control unit obtains the real-time working condition information of the engine through the analog-digital conversion channel and the communication bus, and the real-time working condition information at least includes the rotation speed data, the air inlet flow rate data and the air inlet flow data; The real-time working condition information is checked for validity by an engine electronic control unit, wherein if the real-time working condition information is invalid information, the engine electronic control unit controls the cross-section valve group (7) to be in a safe full-open position, and if the real-time working condition information is valid information, the engine electronic control unit starts to determine the running state of the engine; If the engine speed is higher than a preset threshold value, the engine electronic control unit determines that the engine is in a normal running state; Flow data of the intake pipe (3) is acquired; Target flow area data is obtained according to a preset relationship between the acquired flow data of the intake pipe (3) and the target flow area, and the opening of the cross-section valve group (7) is controlled according to the obtained target flow area data.

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