Hydrogen engine, control method thereof, and vehicle

Abstract

This invention belongs to the field of automotive manufacturing technology and discloses a hydrogen engine and its control method, as well as a vehicle. The engine includes a crankcase ventilation system, a hydrogen scavenging system, and an ECU. An air filter is installed in the engine intake pipe. The crankcase injection pipe is connected to the engine intake pipe and the crankcase. Both a low-load outlet branch and a high-load outlet branch are connected in parallel to the crankcase outlet pipe and the engine intake pipe. A vacuum pump is installed on the high-load outlet branch. Hydrogen concentration sensors are respectively installed in the crankcase, on the crankcase outlet pipe, and on the intake manifold. A scavenging pipe is equipped with a scavenging pump and is connected to the hydrogen rail and the intake manifold. The low-load outlet branch is connected to the scavenging pipe. The crankcase ventilation system and the hydrogen scavenging system are electrically connected to the ECU. This invention monitors the engine hydrogen concentration. The vacuum pump delivers hydrogen from the crankcase and pipes into the cylinders for combustion. When the engine is stopped, it effectively scavenges and burns the hydrogen in the hydrogen rail, improving engine safety.

Description

Technical Field

[0001] This invention belongs to the field of automobile manufacturing technology, specifically relating to a hydrogen engine and its control method, and a vehicle. Background Technology

[0002] The working principle of an engine is that fuel burns in the combustion chamber, pushing the piston to reciprocate within the cylinder. This reciprocating motion is converted into rotational motion via the crankshaft and connecting rod to perform work. Although piston rings are designed to reduce blow-by from the cylinder to the crankcase, it's impossible to completely prevent blow-by, especially during the compression and power cycles when cylinder pressure is higher and blow-by is greater. Blow-by contains high-temperature fuel, combustion exhaust gases, and water vapor. If this blow-by remains in the crankcase, it can damage the engine and even pose a danger. Furthermore, during engine shutdown, the pressure in the hydrogen rail gradually decreases, reducing the pressure difference between the inside and outside of the rail and restricting gas flow. This prevents hydrogen from being completely injected into the cylinder for combustion. Residual hydrogen in the rail can slowly seep into the cylinder through poorly sealed hydrogen injectors after engine shutdown, and may even enter the intake and exhaust pipes through the intake and exhaust valves, posing a safety hazard.

[0003] Hydrogen is an ideal engine fuel as a clean energy source. During operation, high-temperature unburned hydrogen, water vapor, and other combustion products can seep into the crankcase of a hydrogen engine. After the engine stops, residual hydrogen in the crankcase may also seep into the cylinders and intake / exhaust lines. Hydrogen has a flammable concentration range of 4%-75%, posing a risk of deflagration in the confined crankcase or intake / exhaust lines, necessitating enhanced monitoring, forced ventilation, and scavenging measures.

[0004] Patent CN114320529 A describes a crankcase ventilation system, a vehicle, and a control method for the crankcase ventilation system. It proposes a method to draw gas from the crankcase back to the turbocharger pre-pipeline using an active oil-gas separator. A pipeline connects the intake manifold and the crankcase, and the pipeline's opening and closing is controlled by a solenoid valve. This crankcase ventilation system and control method only opens the solenoid valve to replenish air to the crankcase through the intake manifold when the engine is operating under high load conditions. When the engine is operating under low load conditions, the blow-by gas in the crankcase still needs to be expelled as soon as possible. The air taken from the intake manifold is a mixture of fresh air and crankcase blow-by gas, essentially meaning that the blow-by gas is expelled and then re-delivered to the crankcase, resulting in low efficiency. Patent CN113550810A, concerning a crankcase ventilation system and its control method, proposes a crankcase ventilation system and its control method that utilizes a crankcase regulator to adjust the speed of the crankcase gas flow to the oil-gas separator, thereby changing the oil-gas separation efficiency. However, this method cannot effectively control the hydrogen in the crankcase and the residual hydrogen in the crankcase, making it difficult to apply to hydrogen engines. Patent CN112282891A, concerning a crankcase ventilation control method and system, proposes a method for switching the connection position between the crankcase outlet and the intake pipe based on the external ambient temperature. This method can only passively expel blow-by gas based on the pressure difference between the crankcase and the intake pipe, and cannot achieve active control. Furthermore, it cannot monitor and control the hydrogen concentration in the crankcase in real time.

[0005] In summary, existing crankcase ventilation technologies all have their limitations and cannot specifically address the safety hazards caused by hydrogen-containing gas blow-through in the crankcase during hydrogen engine operation and residual hydrogen leakage in the rail after shutdown. They are insufficient to meet the safe operation requirements of hydrogen engines. Therefore, developing a technical solution that can effectively control hydrogen in the crankcase and residual hydrogen in the rail of a hydrogen engine and avoid safety risks has become an urgent technical problem to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a hydrogen engine and its control method, as well as a vehicle. Through a crankcase ventilation system and a hydrogen scavenging system and their control method, the hydrogen concentration in the engine body, intake manifold, and crankcase piping can be monitored, allowing for timely detection of hydrogen safety risks. A vacuum pump control strategy re-introduces hydrogen from the crankcase and piping into the cylinders for combustion, thereby reducing the hydrogen concentration and ensuring safe engine operation and passenger safety. During engine shutdown, the invention effectively scavenges and combusts hydrogen in the clean hydrogen rail, preventing hydrogen leakage into the cylinders or intake / exhaust manifolds after shutdown, thus ensuring safety during shutdown.

[0007] The specific details of the plan are as follows:

[0008] A hydrogen engine includes a crankcase ventilation system, a hydrogen scavenging system, and an engine control unit. The crankcase ventilation system includes a crankcase, an engine intake manifold, a crankcase make-up air manifold, a crankcase outlet manifold, a low-load outlet branch, a high-load outlet branch, and a hydrogen concentration sensor assembly. An air filter is installed at the intake end of the engine intake manifold. The two ends of the crankcase make-up air manifold are connected to the engine intake manifold after the air filter and the crankcase, respectively. The low-load outlet branch and the high-load outlet branch are connected in parallel, and both ends of each are connected to the crankcase outlet manifold and the air filter, respectively. The engine intake pipe after the purifier is connected, and a gas delivery device is installed on the high-load outlet branch for effective discharge of crankcase exhaust gas. Hydrogen concentration sensor components are respectively installed inside the crankcase, on the crankcase outlet pipe, and on the outlet end of the engine intake pipe. The hydrogen purging system includes a hydrogen rail, a purging pipe, and a purging pump. The two ends of the purging pipe are connected to the hydrogen rail and the outlet end of the engine intake pipe, respectively. The purging pump is installed on the purging pipe, and the low-load outlet branch is connected to the purging pipe. The crankcase ventilation system and the hydrogen purging system are electrically connected to the engine control unit.

[0009] The crankcase ventilation system of this invention mainly includes an engine crankcase and associated crankcase air supply lines, engine intake lines, crankcase outlet lines, low-load outlet branches, and high-load outlet branches. The engine intake lines include an air filter, a turbocharger, a throttle valve, and an intake manifold. The crankcase air supply line connects to the air filter in the intake lines at its inlet and to the crankcase at its outlet, supplying fresh air into the crankcase. An oil separator is installed on the crankcase outlet line to separate engine oil from the air coming from the crankcase. The low-load outlet branch connects to the oil separator at its inlet and to the intake manifold at its outlet. The inlet of the high-load branch is connected after the oil-gas separator, and the outlet is connected to the engine intake pipe before the turbocharger. A gas delivery device is installed on the high-load branch; preferably, a vacuum pump is used. This allows for effective discharge of crankcase exhaust gas when the engine is operating under high load conditions, and also actively extracts crankcase gas to ensure safety when the hydrogen concentration in the crankcase is too high. One-way valves are installed on the crankcase make-up gas line, the low-load outlet branch, and the high-load outlet branch to ensure unidirectional gas flow. A first hydrogen concentration sensor, a second hydrogen concentration sensor, a third hydrogen concentration sensor, and a fourth hydrogen concentration sensor are installed on the side of the crankcase near the intake pipe, the side near the exhaust pipe, the pipe before the oil-gas separator, and the intake manifold, respectively. This enables real-time monitoring of the hydrogen concentration in the crankcase, the crankcase outlet gas, and the engine cylinder intake gas. Combined with hydrogen concentration monitoring and active ventilation strategies, this ensures the safety of the hydrogen engine. The hydrogen scavenging system of this invention mainly includes a hydrogen rail, a hydrogen injector, a scavenging line, a one-way valve, and a scavenging pump. During engine shutdown, the scavenging pump operates, and residual hydrogen in the hydrogen rail, under the negative pressure created by the scavenging pump, enters the intake manifold through the scavenging line and the one-way valve, and then enters the cylinder for combustion, ensuring safety during and after engine shutdown.

[0010] Furthermore, the engine intake pipe also includes a turbocharger, a throttle valve, and an intake manifold. The turbocharger is located on the engine intake pipe after the air filter. The intake manifold is located on the outlet end of the engine intake pipe. The throttle valve is located on the engine intake pipe between the turbocharger and the intake manifold. The intake end of the low-load outlet branch is connected to the crankcase outlet pipe, and the outlet end of the low-load outlet branch is connected to the intake manifold. The intake end of the high-load outlet branch is connected to the crankcase outlet pipe, and the outlet end of the high-load outlet branch is connected to the engine intake pipe before the turbocharger. The gas delivery device includes a vacuum pump, which is located on the high-load outlet branch. The two ends of the scavenging pipe are connected to the hydrogen rail and the intake manifold, respectively.

[0011] Furthermore, the crankcase outlet pipeline also includes an oil-gas separator, which is fixed on the crankcase outlet pipeline. The inlet end of the low-load outlet branch and the inlet end of the high-load outlet branch are both connected to the crankcase outlet pipeline after the oil-gas separator.

[0012] Furthermore, one-way valves are installed on the crankcase air supply line, the low-load outlet branch, the high-load outlet branch, and the scavenging line.

[0013] Furthermore, the hydrogen scavenging system also includes a hydrogen injector, which is equipped with a dedicated driver chip to receive control signals, drive the injector switch, and control the amount of hydrogen injected. The hydrogen injector is fixedly connected to the hydrogen rail.

[0014] Furthermore, it also includes the engine exhaust pipe, and the hydrogen concentration sensor assembly includes a first hydrogen concentration sensor, a second hydrogen concentration sensor, a third hydrogen concentration sensor, and a fourth hydrogen concentration sensor. The first and second hydrogen concentration sensors are both located inside the crankcase, near the engine intake pipe and the engine exhaust pipe, respectively. The third hydrogen concentration sensor is located on the crankcase outlet pipe of the oil-gas separator, and the fourth hydrogen concentration sensor is located on the intake manifold.

[0015] A control method for the hydrogen engine, comprising the following steps:

[0016] S1. Determine whether the engine is in the normal operating stage. If the engine is in the normal operating stage, proceed to step S2; otherwise, proceed to step S3.

[0017] S2. Obtain the measured values ​​from the first, second, third, and fourth hydrogen concentration sensors, and determine whether the hydrogen concentration measured by these sensors exceeds the maximum limit. If the measured concentration of any one sensor exceeds the maximum limit, the vacuum pump operates at its maximum capacity speed. If the measured concentrations of all sensors do not exceed the maximum limit, then it is determined whether the hydrogen concentrations measured by the first and second hydrogen concentration sensors exceed half of the maximum limit. If the measured concentrations of the first and second hydrogen concentration sensors do not exceed half of the maximum limit, the vacuum pump operates at a speed of [speed value missing]. Operation The calculation formula is: ,in, The larger of the hydrogen concentrations measured by the first and second hydrogen concentration sensors is given. The rotational speed at maximum capacity of the vacuum pump is determined. If the measured concentration of the first or second hydrogen concentration sensor exceeds half of the maximum limit, it is determined whether the increase in the measured concentration of the first or second hydrogen concentration sensor within the past time T0 exceeds P0. If so, the vacuum pump operates at its maximum capacity rotational speed. If not, then the vacuum pump will operate at 0.5 times the speed. The rotational speed is determined by calibration.

[0018] S3. Based on the measured value from the hydrogen rail pressure sensor. With preset rail pressure threshold and Based on the comparison results, the hydrogen injector drive current issued by the engine control unit is selected. : ,in This is the drive current amplification factor. This is the rail pressure value for normal engine operation. The rail voltage threshold for driving current switching. To meet the normal drive current waveform requirements of the hydrogen injector, The switching is achieved through a dedicated injector drive chip integrated into the engine control unit; the hydrogen rail pressure is less than a preset threshold. At this point, the engine control unit shuts off the hydrogen injector drive and starts the scavenging pump. Hydrogen in the hydrogen rail enters the intake manifold via the scavenging pump and then enters the cylinder for combustion. The scavenging pump speed C is adjusted in real time. in, To clear the speed at which the pump operates at maximum power.

[0019] Furthermore, in step S1, the method for obtaining the hydrogen concentration measurement value from the hydrogen concentration sensor includes: ① The analog output type sensor transmits the measured voltage value to the engine control unit, and the engine control unit processes the analog signal and calculates the hydrogen concentration; ② The hydrogen concentration is directly transmitted to the engine control unit through the vehicle communication protocol.

[0020] Furthermore, in step 1, the maximum limit for hydrogen concentration is selected as the hydrogen explosion limit, i.e., a hydrogen concentration of 40,000 ppm. In step S3, 0.8× .

[0021] A vehicle comprising the aforementioned hydrogen engine.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] ① The crankcase ventilation system of the present invention can ensure smooth airflow at the crankcase outlet regardless of whether the engine is operating under high or low load conditions;

[0024] ② Most existing crankcase scavenging systems can only rely on the engine itself to achieve passive scavenging, and cannot achieve active scavenging. That is, the scavenging rate and scavenging time are uncontrollable. This invention sets up a vacuum pump in the high-load scavenging branch, which can achieve controllable purging of crankcase gas, has stronger adaptability, and has a better purging effect under high load conditions.

[0025] ③ Existing crankcase ventilation systems lack monitoring methods for hydrogen concentration within the crankcase, making it difficult to detect changes in hydrogen concentration and react promptly. Furthermore, they lack forced ventilation and suitable control methods, failing to guarantee the safe and reliable operation of the hydrogen engine. This invention provides a crankcase ventilation system and control method that monitors hydrogen concentration in the crankcase in real time and integrates engine operating conditions. When the hydrogen concentration is low and relatively stable, the forced ventilation system maintains low operating power, saving energy while ensuring safety. When the hydrogen concentration growth rate is high, it can curb the increase in hydrogen concentration within the crankcase, achieving predictive control. Once the monitoring system detects a high hydrogen concentration, forced ventilation can be used to promptly reduce the hydrogen concentration in the crankcase, ensuring the safe and reliable operation of the hydrogen engine.

[0026] ④ In view of the problem that existing methods do not consider the safety risks caused by residual hydrogen in the hydrogen rail flowing into the cylinder and intake and exhaust pipes, this invention designs a hydrogen purging pipeline connecting the hydrogen rail and the intake manifold. Combined with the shutdown process control method, it can effectively reduce the safety risks caused by uncontrollable hydrogen flow in the rail. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the hydrogen engine system of the present invention.

[0028] Figure 2 This is a flowchart of the control method for the hydrogen engine of the present invention.

[0029] In the picture:

[0030] 1. Crankcase; 2. Engine intake manifold; 2.1. Air filter; 2.2. Turbocharger; 2.3. Throttle valve; 2.4. Intake manifold; 3. Crankcase air supply line; 4. Crankcase outlet line; 4.1. Oil-gas separator; 5. Low-load outlet branch; 6. High-load outlet branch; 6.1. Gas delivery device; 7. Hydrogen concentration sensor assembly; 7.1. First hydrogen concentration sensor; 7.2. Second hydrogen concentration sensor; 7.3. Third hydrogen concentration sensor; 7.4. Fourth hydrogen concentration sensor; 8. Hydrogen rail; 9. Purge line; 10. Purge pump; 11. Check valve; 12. Hydrogen injector; 13. Engine exhaust manifold; 14. Engine cylinder. Detailed Implementation

[0031] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention. Furthermore, it should be noted that, for ease of description, only the parts related to the present invention are shown in the accompanying drawings, not all of them.

[0032] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions.

[0033] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0034] The following combination Figure 1 , Figure 2 The present invention will be described in conjunction with the embodiments:

[0035] Example 1:

[0036] A hydrogen engine, see Figure 1As shown, the system includes a crankcase ventilation system, a hydrogen scavenging system, and an engine control unit. The crankcase ventilation system includes a crankcase 1, an engine intake manifold 2, a crankcase make-up air manifold 3, a crankcase outlet manifold 4, a low-load outlet branch 5, a high-load outlet branch 6, and a hydrogen concentration sensor assembly 7. An air filter 2.1 is installed at the intake end of the engine intake manifold 2. The two ends of the crankcase make-up air manifold 3 are connected to the engine intake manifold 2 after the air filter 2.1 and the crankcase 1, respectively. The low-load outlet branch 5 and the high-load outlet branch 6 are connected in parallel, and both ends of the latter are connected to the crankcase outlet manifold 4 and the air filter 2, respectively. The engine intake pipe 2 is connected to the crankcase 1. A gas delivery device 6.1 is installed on the high-load outlet branch 6 for the effective discharge of exhaust gas from the crankcase 1. The hydrogen concentration sensor assembly 7 is respectively installed inside the crankcase 1, on the crankcase outlet pipe 4, and on the outlet end of the engine intake pipe 2. The hydrogen scavenging system includes a hydrogen rail 8, a scavenging pipe 9, and a scavenging pump 10. The two ends of the scavenging pipe 9 are connected to the hydrogen rail 8 and the outlet end of the engine intake pipe 2, respectively. The scavenging pump is installed on the scavenging pipe 9. The low-load outlet branch 5 is connected to the scavenging pump 10. The crankcase ventilation system and the hydrogen scavenging system are electrically connected to the engine control unit.

[0037] The engine intake pipe 2 also includes a turbocharger 2.2, a throttle valve 2.3, and an intake manifold 2.4. The turbocharger 2.2 is located on the engine intake pipe 2 after the air filter 2.1. The intake manifold 2.4 is located on the outlet end of the engine intake pipe 2. The throttle valve 2.3 is located on the engine intake pipe 2 between the turbocharger 2.2 and the intake manifold 2.4. The intake end of the low-load outlet branch 5 is connected to the crankcase outlet pipe 4, and the outlet end of the low-load outlet branch 5 is connected to the intake manifold 2.4. The intake end of the high-load outlet branch 6 is connected to the crankcase outlet pipe 4, and the outlet end of the high-load outlet branch 6 is connected to the engine intake pipe 2 before the turbocharger 2.2. The gas delivery device 6.1 includes a vacuum pump, which is located on the high-load outlet branch 6. The two ends of the scavenging pipe 9 are connected to the hydrogen rail 8 and the intake manifold 2.4, respectively.

[0038] The crankcase outlet pipe 4 also includes an oil-gas separator 4.1, which is fixed on the crankcase outlet pipe 4. The inlet end of the small load outlet branch 5 and the inlet end of the large load outlet branch 6 are both connected to the crankcase outlet pipe 4 after the oil-gas separator 4.1.

[0039] One-way valves 11 are installed on crankcase air supply line 3, low-load outlet branch line 5, high-load outlet branch line 6 and scavenging line 9.

[0040] The hydrogen scavenging system also includes a hydrogen injector 12, which is equipped with a dedicated driver chip to receive control signals, drive the injector switch, and control the amount of hydrogen injected. The hydrogen injector 12 is fixedly connected to the hydrogen rail 8.

[0041] It also includes an engine exhaust pipe 13, and a hydrogen concentration sensor assembly 7 comprising a first hydrogen concentration sensor 7.1, a second hydrogen concentration sensor 7.2, a third hydrogen concentration sensor 7.3, and a fourth hydrogen concentration sensor 7.4. The first and second hydrogen concentration sensors 7.1 and 7.2 are both located inside the crankcase 1, near the engine intake pipe 2 and engine exhaust pipe 13, respectively. The third hydrogen concentration sensor 7.3 is located on the crankcase outlet pipe 4 of the oil-gas separator 4.1, and the fourth hydrogen concentration sensor 7.4 is located on the intake manifold 2.4. The first, second, and third hydrogen concentration sensors 7.1, 7.2, 7.3, and 7.4 are used for real-time monitoring of the hydrogen concentration in the gas inside the crankcase 1, the gas at the crankcase 1 outlet, and the hydrogen intake air of the engine cylinder 14. Combined with hydrogen concentration monitoring and active ventilation strategies, this ensures the safety of the hydrogen engine.

[0042] Example 2:

[0043] The present invention also provides a control method for the aforementioned hydrogen engine, see below. Figure 2 As shown, the steps include:

[0044] S1. Determine whether the engine is in the normal operating stage. If the engine is in the normal operating stage, proceed to step S2; otherwise, proceed to step S3.

[0045] S2. Obtain the measured values ​​of the first hydrogen concentration sensor 7.1, the second hydrogen concentration sensor 7.2, the third hydrogen concentration sensor 7.3, and the fourth hydrogen concentration sensor 7.4. The methods for obtaining the hydrogen concentration measurement values ​​of the hydrogen concentration sensors include, but are not limited to: ① The analog output type sensor transmits the measured voltage value to the engine control unit, and the engine control unit processes the analog signal and calculates the hydrogen concentration; ② The hydrogen concentration is directly transmitted to the engine control unit through the vehicle communication protocol.

[0046] The system determines whether the hydrogen concentrations measured by the first hydrogen concentration sensor 7.1, the second hydrogen concentration sensor 7.2, the third hydrogen concentration sensor 7.3, and the fourth hydrogen concentration sensor 7.4 exceed the maximum limit. The maximum limit for hydrogen concentration is selected as the hydrogen explosion limit, i.e., a hydrogen concentration of 40,000 ppm. If the concentration measured by any of the sensors exceeds the maximum limit, the vacuum pump will operate at its maximum capacity speed. If the measured concentrations of all sensors do not exceed the maximum limit, then it is determined whether the hydrogen concentrations measured by the first hydrogen concentration sensor 7.1 and the second hydrogen concentration sensor 7.2 exceed half of the maximum limit. If the measured concentrations of the first hydrogen concentration sensor 7.1 and the second hydrogen concentration sensor 7.2 do not exceed half of the maximum limit, then the vacuum pump operates at a speed of... Operation The calculation formula is: ,in, The larger of the hydrogen concentration values ​​measured by the first hydrogen concentration sensor 7.1 and the second hydrogen concentration sensor 7.2 is used. The rotational speed at maximum capacity of the vacuum pump is determined. If the measured concentration of the first hydrogen concentration sensor 7.1 or the second hydrogen concentration sensor 7.2 exceeds half of the maximum limit, it is determined whether the increase in the measured concentration of the first hydrogen concentration sensor 7.1 or the second hydrogen concentration sensor 7.2 within the past time T0 exceeds P0. If so, the vacuum pump operates at its maximum capacity rotational speed. If not, then the vacuum pump will operate at 0.5 times the speed. The rotational speed is determined by calibration.

[0047] S3. Based on the pressure sensor readings of hydrogen rail 8 With preset rail pressure threshold and Based on the comparison results, the hydrogen injector drive current issued by the engine control unit is selected. : ,in This is the drive current amplification factor. This is the rail pressure value for normal engine operation. The rail voltage threshold for driving current switching. 0.8× . To meet the normal drive current waveform requirements of hydrogen injector 12, The switching is achieved through a dedicated injector drive chip integrated into the engine control unit. By amplifying the drive current of the hydrogen injector, it can enhance gas flow and improve the efficiency of hydrogen injection into the cylinder when the pressure in the hydrogen rail is low, thereby minimizing the hydrogen rail pressure. The hydrogen rail pressure is below a preset threshold. Because the pressure difference between the hydrogen rail and the cylinder is too small, the hydrogen injection efficiency is extremely low, making it difficult to completely purge the hydrogen from the rail. At this time, the engine control unit shuts off the hydrogen injector 12 drive and starts the scavenging pump 10. The hydrogen in the hydrogen rail 8 enters the intake manifold 2.4 through the scavenging pump 10, and then enters the cylinder for combustion. The speed C of the scavenging pump 10 is adjusted in real time. in, The maximum cleaning efficiency is achieved by adjusting the speed at which the cleaning pump 10 operates at maximum power.

[0048] The above-described crankcase ventilation and corresponding control methods for hydrogen engines enable monitoring of hydrogen concentration in the engine body, engine intake manifold 2, and crankcase piping. This allows for timely detection of hydrogen safety risks in the engine. A vacuum pump control strategy re-introduces hydrogen from the crankcase and piping into the cylinders for combustion, thereby reducing hydrogen concentration and ensuring safe engine operation and passenger safety. During engine shutdown, the designed hydrogen scavenging system and its control methods effectively scaveng and combust hydrogen in the clean hydrogen rail, preventing hydrogen leakage into the cylinders or intake / exhaust pipes after shutdown, thus ensuring safety during shutdown.

[0049] Example 3:

[0050] The present invention also provides a vehicle including the aforementioned hydrogen engine.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hydrogen engine, characterized in that, The system includes a crankcase ventilation system, a hydrogen scavenging system, and an engine control unit. The crankcase ventilation system includes a crankcase (1), an engine intake pipe (2), a crankcase make-up air pipe (3), a crankcase outlet pipe (4), a low-load outlet branch (5), a high-load outlet branch (6), and a hydrogen concentration sensor assembly (7). An air filter (2.1) is provided on the intake end of the engine intake pipe (2). The two ends of the crankcase make-up air pipe (3) are connected to the engine intake pipe (2) after the air filter (2.1) and the crankcase (1), respectively. The low-load outlet branch (5) and the high-load outlet branch (6) are connected in parallel, and both ends of the latter are connected to the crankcase outlet pipe (4) and the air filter (2.1), respectively. The engine intake pipe (2) is connected, and a gas delivery device (6.1) is provided on the high-load outlet branch (6) for the effective discharge of exhaust gas from the crankcase (1). The hydrogen concentration sensor assembly (7) is respectively installed inside the crankcase (1), on the crankcase outlet pipe (4), and on the outlet end of the engine intake pipe (2). The hydrogen scavenging system includes a hydrogen rail (8), a scavenging pipe (9), and a scavenging pump (10). The two ends of the scavenging pipe (9) are respectively connected to the hydrogen rail (8) and the outlet end of the engine intake pipe (2). The scavenging pump is installed on the scavenging pipe (9). The low-load outlet branch (5) is connected to the scavenging pump (10). The crankcase ventilation system and the hydrogen scavenging system are respectively electrically connected to the engine control unit.

2. The hydrogen engine according to claim 1, characterized in that, The engine intake manifold (2) also includes a turbocharger (2.2), a throttle valve (2.3), and an intake manifold (2.4). The turbocharger (2.2) is located on the engine intake manifold (2) after the air filter (2.1). The intake manifold (2.4) is located at the outlet end of the engine intake manifold (2). The throttle valve (2.3) is located on the engine intake manifold (2) between the turbocharger (2.2) and the intake manifold (2.4). The intake end of the low-load outlet branch (5) is connected to the crankshaft. The crankcase outlet pipe (4) is connected, the outlet end of the small load outlet branch (5) is connected to the intake manifold (2.4), the intake end of the large load outlet branch (6) is connected to the crankcase outlet pipe (4), the outlet end of the large load outlet branch (6) is connected to the engine intake pipe (2) before the turbocharger (2.2), the gas delivery device (6.1) includes a vacuum pump, the vacuum pump is installed on the large load outlet branch (6), and the two ends of the cleaning pipe (9) are connected to the hydrogen rail (8) and the intake manifold (2.4) respectively.

3. The hydrogen engine according to claim 1, characterized in that, The crankcase outlet pipe (4) also includes an oil-gas separator (4.1), which is fixed on the crankcase outlet pipe (4). The inlet end of the small load outlet branch (5) and the inlet end of the large load outlet branch (6) are both connected to the crankcase outlet pipe (4) after the oil-gas separator (4.1).

4. The hydrogen engine according to claim 1, characterized in that, One-way valves (11) are provided on the crankcase air supply line (3), the small load outlet branch (5), the large load outlet branch (6), and the scavenging line (9).

5. The hydrogen engine according to claim 1, characterized in that, The hydrogen scavenging system also includes a hydrogen injector (12), which is equipped with a dedicated drive chip to receive control signals, drive the injector switch, and control the amount of hydrogen injected. The hydrogen injector (12) is fixedly connected to the hydrogen rail (8).

6. The hydrogen engine according to claim 1, characterized in that, It also includes an engine exhaust pipe (13), and a hydrogen concentration sensor assembly (7) including a first hydrogen concentration sensor (7.1), a second hydrogen concentration sensor (7.2), a third hydrogen concentration sensor (7.3) and a fourth hydrogen concentration sensor (7.4). The first hydrogen concentration sensor (7.1) and the second hydrogen concentration sensor (7.2) are both located inside the crankcase (1) near the engine intake pipe (2) and the engine exhaust pipe (13) respectively. The third hydrogen concentration sensor (7.3) is located on the crankcase outlet pipe (4) of the oil-gas separator (4.1), and the fourth hydrogen concentration sensor (7.4) is located on the intake manifold (2.4).

7. A control method for a hydrogen engine as described in any one of claims 1-6, characterized in that the steps include... include: S1. Determine whether the engine is in the normal operating stage. If the engine is in the normal operating stage, proceed to step S2; otherwise, proceed to step S3. S2. Obtain the measured values ​​of the first hydrogen concentration sensor (7.1), the second hydrogen concentration sensor (7.2), the third hydrogen concentration sensor (7.3), and the fourth hydrogen concentration sensor (7.4), and determine whether the hydrogen concentration measured by the first hydrogen concentration sensor (7.1), the second hydrogen concentration sensor (7.2), the third hydrogen concentration sensor (7.3), and the fourth hydrogen concentration sensor (7.4) exceeds the maximum limit. If the measured concentration of any sensor exceeds the maximum limit, the vacuum pump operates at its maximum capacity speed. If the measured concentrations of all sensors do not exceed the maximum limit, then it is determined whether the hydrogen concentrations measured by the first hydrogen concentration sensor (7.1) and the second hydrogen concentration sensor (7.2) exceed half of the maximum limit. If the measured concentrations of the first hydrogen concentration sensor (7.1) and the second hydrogen concentration sensor (7.2) do not exceed half of the maximum limit, then the vacuum pump operates at a speed of [speed value missing]. Operation The calculation formula is: ,in, The larger of the hydrogen concentrations measured by the first hydrogen concentration sensor (7.1) and the second hydrogen concentration sensor (7.2) is used. The rotational speed is the maximum capacity of the vacuum pump. If the measured concentration of the first hydrogen concentration sensor (7.1) or the second hydrogen concentration sensor (7.2) exceeds half of the maximum limit, then it is determined whether the increase in the measured concentration of the first hydrogen concentration sensor (7.1) or the second hydrogen concentration sensor (7.2) within the past T0 time period exceeds P. 0, If so, the vacuum pump operates at its maximum capacity speed. If not, then the vacuum pump will operate at 0.5 times the speed. The rotational speed is determined by calibration. S3. Based on the pressure sensor readings of the hydrogen rail (8) With preset rail pressure threshold and Based on the comparison results, the hydrogen injector drive current issued by the engine control unit is selected. : ,in This is the drive current amplification factor. This is the rail pressure value for normal engine operation. The rail voltage threshold for driving current switching. To meet the normal drive current waveform required for the hydrogen injector (12), The switching is achieved through a dedicated injector drive chip integrated in the engine control unit; the hydrogen rail (8) pressure is less than a preset threshold. At this time, the engine control unit shuts off the hydrogen injector (12) drive and turns on the scavenging pump (10). The hydrogen in the hydrogen rail (8) enters the intake manifold (2.4) through the scavenging pump (10) and then enters the cylinder for combustion. The rotational speed C of the scavenging pump (10) is adjusted in real time. in, The speed at which the sweep pump (10) operates at maximum power.

8. The control method for a hydrogen engine according to claim 7, characterized in that, In step S1, the method for obtaining the hydrogen concentration measurement value from the hydrogen concentration sensor includes: ① The analog output type sensor transmits the measured voltage value to the engine control unit, and the engine control unit processes the analog signal and calculates the hydrogen concentration; ② The hydrogen concentration is directly transmitted to the engine control unit through the vehicle communication protocol.

9. The control method for a hydrogen engine according to claim 7, characterized in that, In step 1, the maximum limit for hydrogen concentration is selected as the hydrogen explosion limit, i.e., a hydrogen concentration of 40,000 ppm. In step S3, 0.8× .

10. A vehicle, characterized in that, Including the hydrogen engine as described in any one of claims 1-6.

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