Hydrogen safety management structure for crankcase of hydrogen engine and control method of hydrogen safety management structure

Abstract

The invention discloses a hydrogen safety management structure of a hydrogen engine crankcase. The hydrogen safety management structure comprises a gas inlet pipe, a gas supplementing header pipe, a control valve, a cylinder body, a plurality of sensors and at least two branch pipes. Wherein the air inlet pipe is connected with an air source; one end of the air supply header pipe is communicated with the air inlet pipe, and the other end of the air supply header pipe is connected with the branch pipe; the branch pipe is communicated with the air cylinder body through an air supplementing connector so that air can be supplemented to a crankcase. The sensor is arranged in the cylinder body and is used for detecting the concentration of hydrogen in the crankcase; the control valve is arranged between the air supply main pipe and the branch pipe so as to adjust the amount of air entering the crankcase. Aiming at the hydrogen leakage safety pain point of the hydrogen engine crankcase, an integrated management and control structure of directional gas supply and accurate detection is constructed, and the problem that a traditional engine does not have special crankcase hydrogen concentration management and control hardware is solved.

Description

Technical Field

[0001] This invention relates to the field of hydrogen engine technology, and in particular to a hydrogen safety management structure and control method for a hydrogen engine crankcase. Background Technology

[0002] Against the backdrop of accelerated global energy conservation and emission reduction strategies, the development and application of clean energy has become one of the core directions for low-carbon transformation in the transportation sector. Among them, hydrogen, as a fuel capable of achieving zero carbon emissions throughout its entire life cycle, has attracted much attention from the industry due to its wide availability and high energy density, making its development potential in engine power systems highly promising. However, the unique physicochemical properties of hydrogen pose severe safety challenges in its practical applications: on the one hand, hydrogen molecules are extremely small, making them the fastest diffusing substance among all gases. Even with tiny gaps in the equipment structure, leaks are highly likely to occur, and once leaked, they can quickly spread throughout the space; on the other hand, the lower explosive limit of hydrogen is only 4% (volume concentration), far lower than that of traditional fuels. Even a small leak can cause a localized area to reach a flammable concentration. Furthermore, its ignition energy is only 0.02 millijoules, less than one-tenth of the ignition energy of natural gas (methane) (approximately 0.29 millijoules). Tiny electrostatic sparks, metal-on-metal sparks, or even the weak arc of an electrical switch are enough to ignite a hydrogen-air mixture, further amplifying the safety risks after a leak.

[0003] For hydrogen engines, the aforementioned safety risks are particularly pronounced in the crankcase system: during engine operation, the hydrogen-gas mixture in the combustion chamber inevitably leaks into the crankcase through the gap between the piston rings and cylinder walls. Because the crankcase is a relatively enclosed space, the leaked hydrogen cannot diffuse and escape on its own, gradually accumulating within the case. Given hydrogen's low explosive limit and flammability, once the hydrogen concentration in the crankcase rises to the 4% flammability threshold, even a tiny internal mechanical spark or static electricity can trigger detonation or even an explosion. This problem has become a key safety bottleneck restricting the large-scale deployment of hydrogen engines. How to effectively control the hydrogen concentration in the crankcase to prevent it from reaching the dangerous threshold is one of the core issues that urgently needs to be addressed in the field of hydrogen engine safety technology.

[0004] The above background information is provided only to aid in understanding the concept and technical solution of this invention. It does not necessarily belong to the prior art of this patent application. In the absence of clear evidence that the above information was disclosed on the filing date of this patent application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0005] The purpose of this invention is to propose a hydrogen safety management structure and control method for the crankcase of a hydrogen engine, in order to solve the technical problems existing in the prior art, such as easy leakage and accumulation of hydrogen in the crankcase of a hydrogen engine, lack of targeted control hardware, which leads to the hydrogen concentration easily reaching the flammability threshold and prominent safety risks.

[0006] Therefore, this invention proposes a hydrogen safety management structure and control method for the crankcase of a hydrogen engine.

[0007] Preferably, the present invention may also have the following technical features:

[0008] A hydrogen safety management structure for a hydrogen engine crankcase includes an intake manifold, a main air supply manifold, a control valve, a cylinder block, several sensors, and at least two branch pipes.

[0009] The air intake pipe is connected to an air source;

[0010] One end of the main air supply pipe is connected to the air intake pipe, and the other end is connected to the branch pipe;

[0011] The branch pipe is connected to the cylinder block via an air supply connector to supply air to the crankcase.

[0012] The sensor is installed in the cylinder body and is used to detect the concentration of hydrogen in the crankcase;

[0013] The control valve is located between the main air supply pipe and the branch pipe to adjust the amount of air entering the crankcase.

[0014] Preferably, the air source is the air from the engine turbocharger.

[0015] Preferably, the air source is an external vehicle air tank.

[0016] Preferably, there are two branch pipes, corresponding to two air supply connectors; the two air supply connectors are respectively located on the upper front half and the upper rear half of the cylinder body along the length direction.

[0017] Preferably, the air injection connector is located in the upper half of the cylinder block, corresponding to the top area of ​​the crankcase.

[0018] Preferably, the sensor is located in the area of ​​the crankcase with the highest hydrogen concentration.

[0019] Preferably, it also includes a cylinder head cover and an oil-gas separator, with some of the sensors located on the cylinder head cover and at the outlet of the oil-gas separator.

[0020] Preferably, the control valve is an electronically controlled valve, which is signal-connected to the control system of the hydrogen engine to receive control signals from the control system and adjust its opening.

[0021] A control method for a hydrogen safety management structure in the crankcase of a hydrogen engine is also provided, comprising the following steps:

[0022] S1: When the hydrogen engine is running, several sensors collect hydrogen concentration data in the crankcase in real time and transmit the concentration data to the engine control system.

[0023] S2: The control system judges the received hydrogen concentration data. If the concentration is higher than the preset safety limit, it sends a control signal to the control valve to control the control valve to open to the corresponding degree. If the concentration is lower than or equal to the preset safety limit, it controls the control valve to maintain the current opening degree or close it.

[0024] S3: Air from the air source flows into the main air supply pipe through the intake pipe, and then is split by the control valve and enters the crankcase through several branch pipes and corresponding air supply connectors, where it mixes with the hydrogen-containing mixture leaking from the crankcase to dilute the hydrogen concentration.

[0025] S4: The sensors continuously collect hydrogen concentration data in the crankcase and feed it back to the control system. The control system continuously corrects the control signal sent to the control valve based on the feedback data and dynamically adjusts the opening of the control valve until the hydrogen concentration in the crankcase is stably lower than the preset safety limit.

[0026] Preferably, in steps S2 and S4, the preset safety limit is 30%-50% of the lower explosive limit concentration of hydrogen.

[0027] The beneficial effects of this invention compared to the prior art include:

[0028] 1. This invention addresses the safety concerns of hydrogen leakage in the crankcase of hydrogen engines by constructing an integrated control structure of "directional gas replenishment + precise detection," solving the problem of traditional engines lacking dedicated hardware for crankcase hydrogen concentration control. By integrating components such as the intake pipe, main gas replenishment pipe, at least two branch pipes, and sensors, a complete pathway is formed from gas source input to crankcase gas replenishment and concentration detection, filling the hardware gap in hydrogen safety control of the crankcase of hydrogen engines and providing necessary structural support for subsequent dynamic concentration control. Considering the characteristics of hydrogen molecules being small, easily leaking, and having a low lower explosive limit, the layout of "at least two branch pipes + cylinder block connection" can cover multiple areas of the crankcase to achieve directional gas replenishment, avoiding local accumulation of hydrogen in the enclosed space. At the same time, the sensor and the gas replenishment structure work together to capture concentration changes in real time. Compared with solutions without a specific structure, the response efficiency of hydrogen concentration control is improved by more than 50%.

[0029] 2. This invention directly utilizes the air after the engine turbocharger as the replenishment air source, eliminating the need for an additional independent air source device. This saves space in the vehicle layout and allows for continuous replenishment air pressure based on the stable output of the turbocharger. It is particularly suitable for the high-flow replenishment air demand under high engine load conditions, reducing system integration difficulty while ensuring control effectiveness.

[0030] 3. This invention uses an external vehicle air tank as the air source, which has greater independence and is not limited by engine operating conditions; it can still provide a stable air supply flow when the engine is under low load and the turbocharger output is insufficient, and can adapt to the differentiated air supply needs of hydrogen engines of different displacements, thus improving the adaptability of the structure to operating conditions.

[0031] 4. The present invention, through the layout of "two branch pipes + upper half of cylinder block front and rear end air supply connectors", fits the long strip structure of multi-cylinder engine crankcase and can cover the hydrogen accumulation area at both ends of the crankcase; at the same time, taking advantage of the characteristic that hydrogen tends to accumulate upwards, it directly supplies air to the high concentration area at the top of the crankcase. Compared with other layouts, the dilution efficiency of peak hydrogen concentration is increased by more than 30%, and the structure is simple and easy to assemble. Attached Figure Description

[0032] Figure 1 This is a structural schematic diagram of a specific embodiment of the present invention.

[0033] Figure 2 This is a cloud map of hydrogen molar concentration without the gas replenishment structure of this invention.

[0034] Figure 3 This is a hydrogen molar concentration cloud map of a specific embodiment of the present invention.

[0035] Explanation of reference numerals in the attached diagram: 1-Intake pipe; 2-Main air supply pipe; 3-Control valve; 4-Cylinder block; 5-Branch pipe; 6-Injection air connector. Detailed Implementation

[0036] This invention discloses a hydrogen safety management structure and control method for a hydrogen engine crankcase, aiming to solve the technical problem of hydrogen leakage from the combustion chamber into the crankcase during hydrogen engine operation, leading to excessive hydrogen concentration and potential safety hazards. The invention will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be emphasized that the following description is merely exemplary and not intended to limit the scope or application of the invention.

[0037] Non-limiting and non-exclusive embodiments will be described with reference to the following figures, wherein the same reference numerals denote the same parts unless otherwise specifically stated.

[0038] Example 1:

[0039] like Figure 1As shown, the hydrogen safety management structure of the crankcase of the hydrogen engine in this embodiment includes an intake pipe 1, a main air supply pipe 2, a control valve 3, a cylinder block 4, several sensors, and at least two branch pipes 5. The intake pipe 1 is connected to an air source and serves as the air source input end of the air supply system; one end of the main air supply pipe 2 is connected to the intake pipe 1, and the other end is connected to the branch pipes 5, serving to collect and distribute air; the branch pipes 5 are connected to the cylinder block 4 through an air supply connector 6 to replenish air to the crankcase; the sensors are installed inside the cylinder block 4 to detect the concentration of hydrogen in the crankcase; the control valve 3 is located between the main air supply pipe 2 and the branch pipes 5 to adjust the amount of air entering the crankcase.

[0040] As one of the preferred embodiments of this invention, the air source is the air after the engine turbocharger. No additional air source device is required; the high-pressure air generated by the turbocharger during engine operation is directly utilized, saving space in the vehicle layout and reducing the difficulty of system integration. The stable air pressure after the turbocharger ensures the continuity of the air supply, making it particularly suitable for the high-flow air supply requirements under high engine load conditions.

[0041] As another preferred embodiment, the air source is an external vehicle air tank. The air source is highly independent and not limited by engine operating conditions. Even under low engine load and insufficient turbocharger output pressure, it can still provide a stable replenishment air flow, ensuring effective control of the hydrogen concentration in the crankcase. The air source pressure can be flexibly adjusted according to actual needs to adapt to the replenishment requirements of hydrogen engines with different displacements.

[0042] As a further limitation of this embodiment, such as Figure 1 As shown, there are two branch pipes 5, corresponding to two air injection connectors 6. The two air injection connectors 6 are respectively located on the upper front half and the upper rear half of the cylinder block 4 along its length. The two branch pipes 5 correspond to the front and rear end layout of the cylinder block 4, which fits the long strip structure of the crankcase of a multi-cylinder engine. The air injection can cover both ends of the crankcase, avoiding the problem of hydrogen accumulation at the ends due to the limited air injection range. The air injection connectors 6 are located in the upper half of the cylinder block 4. Taking advantage of the physical property that hydrogen density is much lower than air and it tends to accumulate upwards, the high concentration of hydrogen in the top of the crankcase is directly diluted. Compared with air injection in the lower half, the dilution efficiency is improved by more than 30%, which can quickly reduce the peak hydrogen concentration.

[0043] Furthermore, the air injection connector 6 is located on the upper half of the cylinder block, corresponding to the top area of ​​the crankcase. The core placement area for the air injection connector is clearly the top of the crankcase, maximizing the upward accumulation of hydrogen gas to achieve "targeted dilution." This layout is not limited to the front and rear ends of the cylinder block and can be adapted to cylinder blocks of different lengths. When the cylinder block is long, an air injection connector can be added in the middle area, improving the versatility and expandability of the structure.

[0044] Specifically, the sensors are distributed in the region of highest hydrogen concentration in the crankcase. The determination of this region is based on a triple foundation of hydrogen physical property analysis, CFD fluid simulation verification, and actual operating condition testing. Hydrogen's density is only 1 / 14.5 that of air, making it the least dense gas in nature. When the engine is running, the hydrogen-air mixture in the combustion chamber leaks into the crankcase through the piston ring gaps. Due to the significant density difference, it naturally rises and cannot remain in the lower half of the crankcase, eventually accumulating in the top of the crankcase, the upper half of the cylinder block, and other high-level spaces. These areas are theoretically the peak hydrogen concentration regions. This is further supported by computational fluid dynamics... Using CFD simulation software, a 3D model of the crankcase was established to simulate the hydrogen diffusion path and concentration distribution under different engine operating conditions (such as idling and high load). The simulated hydrogen molar concentration cloud map clearly showed that the hydrogen concentration values ​​at the top of the crankcase and the upper half of the cylinder block were significantly higher than in other areas. Under some operating conditions, the peak concentration in this area could reach 3-5 times that of the lower half, directly verifying that the high-level area is the area with the highest concentration. During the engine bench test, temporary detection sensors were deployed at different heights and in different areas of the crankcase to collect hydrogen concentration data under all operating conditions. Comparative analysis of the data revealed that the concentration values ​​measured by the sensors in the upper half of the cylinder block and the top of the crankcase were consistently higher and reached the preset safety warning threshold first, further confirming that this area is the core area with the highest hydrogen concentration in the crankcase. Directly deploying sensors in the above-mentioned areas with the highest concentration can directly capture the peak hydrogen concentration in the crankcase, avoiding detection lag or data distortion caused by sensors deployed in low-concentration areas. This ensures that the control system can respond to concentration changes in a timely manner, improving the reliability of hydrogen safety management from the source of detection.

[0045] Specifically, it also includes a cylinder head cover and an oil-gas separator, with some of the sensors installed on the cylinder head cover and at the oil-gas separator outlet. From the physical properties of hydrogen, its density is much lower than air. Hydrogen leaking into the crankcase will continuously rise. As the top sealing component of the crankcase, the cylinder head cover's inner and surrounding areas are prone to forming high-concentration areas of hydrogen accumulation. Installing sensors here can directly capture the peak hydrogen concentration at the top of the crankcase, avoiding the safety hazards of only detecting a localized area inside the cylinder block. The oil-gas separator is a core component of the crankcase ventilation system. The hydrogen-containing mixture in the crankcase enters the oil-gas separator through the ventilation duct for oil-gas separation. The gas at the outlet is the direct discharge channel for the mixture in the crankcase, and its hydrogen concentration directly reflects the overall concentration level within the crankcase. Simultaneously, monitoring the hydrogen concentration at the oil-gas separator outlet can also promptly detect problems such as mixture stagnation or poor discharge in the ventilation system, preventing the accumulation of hydrogen-containing mixtures in the ventilation ducts and the resulting secondary safety risks. The sensor layout at the cylinder head cover and oil-gas separator outlet, together with the sensors inside the cylinder body, forms an "internal + external" collaborative detection network, achieving full coverage of hydrogen concentration in the crankcase and related systems, further improving the accuracy and comprehensiveness of hydrogen concentration detection.

[0046] Specifically, the control valve 4 is an electronically controlled valve, which is connected to the control system of the hydrogen engine to receive control signals from the control system and adjust its opening. The electronically controlled valve has a fast response speed, completing the opening adjustment within 100ms, and compared to a mechanical control valve, it can achieve more precise flow control. Its linkage with the engine control system provides the basis for subsequent closed-loop dynamic control, and it can adjust the gas supply in real time according to concentration changes, avoiding energy waste caused by excessive gas supply.

[0047] In this embodiment, to further improve the gas replenishment effect, the structure of the gas replenishment connector 6 can be optimized. A guide shroud is provided at the outlet end of the gas replenishment connector 6 to allow the air to enter the crankcase in a divergent manner, increasing the contact area between the air and the hydrogen-containing mixture. The sensor is preferably an electrochemical hydrogen sensor with a detection accuracy of up to 0.1%vol, meeting the requirements for accurate detection of hydrogen concentration. The electronic control valve is preferably a proportional solenoid valve with an opening adjustment range of 0-100%, which can realize linear control of the gas replenishment flow.

[0048] To verify the hydrogen dilution effect of the structure of this invention, the inventors conducted CFD fluid simulation and obtained a hydrogen molar concentration cloud map, as shown below. Figure 2 and 3 As shown, Figure 2The crankcase hydrogen concentration distribution without the gas injection structure of this invention is shown. The peak hydrogen molar concentration in the crankcase reaches 0.02 (corresponding to 2% vol), and a large area of ​​red high concentration appears in some local areas (such as the middle section). The concentration distribution is uneven and there is a risk of local exceedance. Figure 3 The concentration distribution after adopting the "dual branch pipe + upper half of cylinder block front and rear end air supply connector" structure of the present invention is as follows: the peak value of hydrogen molar concentration in the crankcase drops to below 0.018, and the whole shows a uniform yellow-green low concentration area without local high concentration accumulation. Figure 2 and 3 The hydrogen molar concentration cloud map visually verifies the dilution effect of the structure of this invention. Compared with the scheme without gas replenishment structure, the peak hydrogen concentration is reduced by more than 10%, effectively controlling the risk of concentration exceeding the standard. The layout of dual branch pipes + upper half connector improves the uniformity of concentration distribution by 50%, avoids dead zones of local high concentration, and solves the technical pain point of "local accumulation" of hydrogen in the crankcase. It also proves that the upper half of the front and rear ends of the cylinder block is a better layout area.

[0049] Example 2:

[0050] This embodiment discloses a control method for a hydrogen safety management structure in the crankcase of a hydrogen engine, including the following steps:

[0051] S1: During hydrogen engine operation, several sensors collect real-time hydrogen concentration data from the crankcase and transmit this data to the engine's control system. In this step, the sensor sampling frequency can be adjusted according to engine operating conditions. When the engine is in start-stop or experiencing sudden load changes, the sampling frequency is adjusted to 10Hz to ensure real-time concentration data. When the engine is in a stable operating condition, the sampling frequency is adjusted to 2Hz to reduce the computational load on the control system. The data collected by the sensors is transmitted to the control system via a CAN bus with a transmission delay of less than 50ms, ensuring that the control system can obtain concentration information promptly.

[0052] S2: The control system judges the received hydrogen concentration data. If the concentration is higher than the preset safety limit, it sends a control signal to the control valve to open the valve to the corresponding degree. If the concentration is lower than or equal to the preset safety limit, it controls the control valve to maintain the current opening degree or close it. In this step, the control system has built-in concentration judgment logic, which can perform average processing on the data collected by multiple sensors to avoid misjudgment caused by the failure of a single sensor. The opening degree adjustment command of the control valve is a digital signal, which can accurately control the opening angle of the valve and achieve precise matching of the supplementary gas flow.

[0053] S3: Air from the air source flows into the main air supply pipe through the intake pipe, and then is diverted by the control valve through several branch pipes and corresponding air supply connectors into the crankcase, where it mixes with the hydrogen-containing mixture leaking from the crankcase to dilute the hydrogen concentration. In this step, the air flow distribution ratio to each branch pipe after being diverted by the control valve can be determined through simulation calculation. For the layout of two branch pipes, the flow distribution ratio of the front and rear branch pipes is preferably 1:1 to ensure uniform dilution of the concentration at the front and rear ends of the crankcase. When air from the engine turbocharger is used as the air source, the control system can activate the bypass valve of the turbocharger to increase the air supply pressure. When an external air tank is used as the air source, the control system can activate the pressure reducing valve of the air tank to stabilize the air supply flow.

[0054] S4: The sensors continuously collect hydrogen concentration data in the crankcase and feed it back to the control system. The control system continuously corrects the control signal sent to the control valve based on the feedback data and dynamically adjusts the opening of the control valve until the hydrogen concentration in the crankcase is stably lower than the preset safety limit.

[0055] The method described in this embodiment constructs a closed-loop control logic of "acquisition-judgment-gas replenishment-feedback correction". Compared with the open-loop control method, it can adjust the gas replenishment amount in real time according to the changes in hydrogen concentration, ensuring that the hydrogen concentration in the crankcase is always within a safe range and avoiding the problem of concentration exceeding the standard due to changes in operating conditions. The control logic is simple and efficient, and can be integrated into the existing engine control system without the need for additional control units, thus reducing the cost of technology implementation.

[0056] Furthermore, the opening degree of the control valve is positively correlated with the hydrogen concentration in the crankcase. That is, the higher the collected hydrogen concentration, the larger the opening degree of the control valve controlled by the control system, resulting in a larger gas injection flow rate. This achieves on-demand regulation of the gas injection flow rate. When the hydrogen concentration is high, the control valve opening is increased to increase the gas injection flow rate and quickly dilute the hydrogen. When the hydrogen concentration approaches the safety limit, the control valve opening is decreased to reduce the gas injection flow rate, avoiding excessive gas injection that could lead to excessive pressure in the crankcase, while also saving gas source energy and improving engine economy.

[0057] In steps S2 and S4, the preset safety limit is 30%-50% of the lower explosive limit of hydrogen. The lower explosive limit of hydrogen is 4% vol. Setting the safety limit to 30%-50% of this, or 1.2%-2% vol, provides sufficient safety redundancy to avoid explosion risks due to concentration fluctuations, while preventing excessive hydrogen replenishment due to an excessively low limit, thus balancing safety and economy. The safety limit can be dynamically adjusted according to the engine's operating conditions. When the engine is under high load and high leakage risk conditions, the limit is adjusted to 1.2% vol to improve the safety level; when the engine is under low load conditions, the limit is adjusted to 2% vol to reduce replenishment energy consumption.

[0058] When the control system detects that the hydrogen concentration data collected by any sensor exceeds 150% of the safety limit, in addition to increasing the opening of the control valve, it also sends a warning signal to the vehicle control system to remind the driver to take measures to reduce the load or stop the engine, thereby further improving safety.

[0059] The diameter of the branch pipes can be designed according to the required gas injection flow. The diameters of the front and rear branch pipes can be adjusted according to the leakage differences between the front and rear ends of the crankcase, achieving precise flow distribution. Specifically, based on the differences in hydrogen leakage in different areas of the crankcase (e.g., larger leakage in the front cylinder), the corresponding branch pipe diameter can be preset (e.g., the front branch pipe diameter is slightly larger than the rear branch pipe), matching the basic gas injection flow to the leakage in each area. The total gas injection flow is dynamically adjusted based on the real-time concentration feedback from the sensor, achieving coordinated control of "preset basic flow + dynamic flow adjustment." The preset basic flow for the branch pipe diameter avoids the problem of "uneven flow distribution" when the control valve is used alone, ensuring the rationality of gas injection in each area. The dynamic adjustment of the total flow by the control valve compensates for the limitations of a fixed branch pipe diameter, achieving flow adaptation under different operating conditions. The synergy of these two aspects allows the gas injection system to achieve both "regional precision" and "global dynamism," improving the efficiency and uniformity of flow control while reducing the adjustment load on the control valve and extending its service life.

[0060] The placement of the gas supply connector can be further optimized through simulation calculations. The simulation software used is CFD fluid simulation software to simulate the hydrogen concentration distribution at different connector locations, and the location with the best concentration uniformity is selected as the final placement location.

[0061] The hydrogen safety management structure and control method for the crankcase of a hydrogen engine of the present invention can effectively solve the safety hazard of hydrogen accumulation in the crankcase of a hydrogen engine through reasonable structural layout and closed-loop control logic. It has the advantages of simple structure, precise control, high safety and good economy, and is suitable for promotion and application in various types of hydrogen engines.

[0062] Those skilled in the art will recognize that numerous variations are possible with respect to the above description, and the embodiments and figures are merely for describing one or more specific implementations.

[0063] Although exemplary embodiments of the invention have been described and illustrated, those skilled in the art will understand that various changes and substitutions can be made thereto without departing from the spirit of the invention. Furthermore, many modifications can be made to adapt specific situations to the doctrine of the invention without departing from the central concepts of the invention described herein. Therefore, the invention is not limited to the specific embodiments disclosed herein, but may include all embodiments and equivalents that fall within the scope of the invention.

Claims

1. A hydrogen safety management structure for a hydrogen engine crankcase, characterized in that, It includes an intake manifold, a main air supply manifold, a control valve, a cylinder block, several sensors, and at least two branch pipes; The air intake pipe is connected to an air source; One end of the main air supply pipe is connected to the air intake pipe, and the other end is connected to the branch pipe; The branch pipe is connected to the cylinder block via an air supply connector to supply air to the crankcase. The sensor is installed in the cylinder body and is used to detect the concentration of hydrogen in the crankcase; The control valve is located between the main air supply pipe and the branch pipe to adjust the amount of air entering the crankcase.

2. The hydrogen safety management structure for the crankcase of a hydrogen engine according to claim 1, characterized in that, The air source is the air supplied by the engine turbocharger.

3. The hydrogen safety management structure for the crankcase of a hydrogen engine according to claim 1, characterized in that, The air source is an external vehicle air tank.

4. The hydrogen safety management structure for the crankcase of a hydrogen engine according to claim 1, characterized in that, The number of branch pipes is two, corresponding to the two air supply connectors; the two air supply connectors are respectively located on the upper half of the front end and the upper half of the rear end of the cylinder body along the length direction.

5. The hydrogen safety management structure for the crankcase of a hydrogen engine according to claim 1 or 4, characterized in that, The air injection connector is located on the upper half of the cylinder block, corresponding to the top area of ​​the crankcase.

6. The hydrogen safety management structure for the crankcase of a hydrogen engine according to claim 1, characterized in that, The sensors are located in the area of ​​the crankcase with the highest hydrogen concentration.

7. The hydrogen safety management structure for the crankcase of a hydrogen engine according to claim 1, characterized in that, It also includes a cylinder head cover and an oil-gas separator, with some of the sensors located on the cylinder head cover and at the outlet of the oil-gas separator.

8. The hydrogen safety management structure for the crankcase of a hydrogen engine according to claim 1, characterized in that, The control valve is an electronically controlled valve, which is connected to the control system of the hydrogen engine to receive control signals from the control system and adjust its opening.

9. A control method for a hydrogen safety management structure in the crankcase of a hydrogen engine as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1: When the hydrogen engine is running, several sensors collect hydrogen concentration data in the crankcase in real time and transmit the concentration data to the engine control system. S2: The control system judges the received hydrogen concentration data. If the concentration is higher than the preset safety limit, it sends a control signal to the control valve to control the control valve to open to the corresponding degree. If the concentration is lower than or equal to the preset safety limit, it controls the control valve to maintain the current opening degree or close it. S3: Air from the air source flows into the main air supply pipe through the intake pipe, and then is split by the control valve and enters the crankcase through several branch pipes and corresponding air supply connectors, where it mixes with the hydrogen-containing mixture leaking from the crankcase to dilute the hydrogen concentration. S4: The sensors continuously collect hydrogen concentration data in the crankcase and feed it back to the control system. The control system continuously corrects the control signal sent to the control valve based on the feedback data and dynamically adjusts the opening of the control valve until the hydrogen concentration in the crankcase is stably lower than the preset safety limit.

10. The control method for the hydrogen safety management structure of the crankcase of a hydrogen engine according to claim 9, characterized in that, In steps S2 and S4, the preset safety limit is 30%-50% of the lower explosive limit concentration of hydrogen.

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