Crankcase ventilation system, hydrogen internal combustion engine and crankcase ventilation system control method

Abstract

The invention belongs to the technical field of engines, and particularly relates to a crankcase ventilation system, a hydrogen internal combustion engine and a crankcase ventilation system control method. The crankcase ventilation system comprises a crankcase, an oil-gas separator, an air filter and a control unit, a hydrogen concentration detection unit is arranged in the crankcase, an inlet of the oil-gas separator is communicated with a first communication port of the crankcase, the air filter is communicated with a second communication port of the crankcase through an air inlet pipeline, and the control unit is connected with the control unit. The air filter selectively communicates with the third communicating port of the crankcase through a first gas supplementing pipeline, and the control unit is in signal connection with the hydrogen concentration detection unit, the oil-gas separator and the air filter. By using the crankcase ventilation system in the technical scheme, the hydrogen concentration in the crankcase is always in a safe range, and the hydrogen internal combustion engine works stably.

Description

Technical Field

[0001] The present invention belongs to the technical field of hydrogen fuel internal combustion engines, and in particular relates to a crankcase ventilation system, a hydrogen internal combustion engine and a crankcase ventilation system control method. Background Art

[0002] Since hydrogen does not produce carbon dioxide after combustion and can be obtained through renewable energy such as solar energy and wind energy, it is considered an ideal energy source or energy carrier. When hydrogen is used as fuel for internal combustion engines, it is very easy to achieve lean combustion, emit less pollutants, and have high thermal efficiency. Therefore, hydrogen fuel internal combustion engines are gradually being used in the automotive field.

[0003] However, compared with internal combustion engines using conventional fuels, leakage or accumulation in hydrogen-fueled internal combustion engines may cause more serious consequences. The explosion limit range of hydrogen is 4.0% to 75.6%, which means that when the volume concentration of hydrogen in the air is within this range, it will explode when it encounters a fire source. When the concentration of hydrogen is lower than 4.0% or higher than 75.6%, it will not explode even if it encounters a fire source. Traditional internal combustion engines usually rely on oil-gas separators to control the gas concentration in the crankcase, but in hydrogen-fueled internal combustion engines, conventional control methods may not be sufficient to effectively control the hydrogen concentration within a safe range.

[0004] Therefore, it is urgent to propose a crankcase ventilation system, a hydrogen internal combustion engine and a crankcase ventilation system control method that can effectively control the hydrogen concentration in the crankcase to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to at least solve the problem of how to prevent the hydrogen concentration inside the crankcase from exceeding the safe range. This purpose is achieved through the following technical solutions:

[0006] A first aspect of the present invention provides a crankcase ventilation system, comprising:

[0007] A crankcase, wherein a hydrogen concentration detection unit is arranged inside the crankcase;

[0008] an oil-gas separator, wherein the inlet of the oil-gas separator is in communication with the first communication port of the crankcase;

[0009] An air filter, the air filter is connected to the second connecting port of the crankcase through an air intake line, and the air filter can be selectively connected to the third connecting port of the crankcase through a first air supply line;

[0010] A control unit is connected to the hydrogen concentration detection unit, the oil-gas separator and the air filter signal.

[0011] By using the crankcase ventilation system in the present technical solution, the hydrogen concentration inside the crankcase is detected by a hydrogen detection unit, and the control unit controls the operation of the oil-gas separator and the air filter according to the hydrogen concentration value collected by the hydrogen detection unit. The oil-gas separator can suck the exhaust gas in the crankcase, thereby changing the internal pressure of the crankcase. The air filter is used to filter out dust and grit in the air to ensure that the air entering the crankcase is clean air. Specifically, when the hydrogen internal combustion engine is operating normally, the filtered air is transported through the intake pipe, and at the same time, the exhaust gas is sucked through the oil-gas separator. At this time, the hydrogen concentration is within the normal range, and the internal pressure of the crankcase is stable. When the hydrogen internal combustion gas runs abnormally and the hydrogen concentration inside the crankcase exceeds the safe range, the control unit controls the oil-gas separator to increase its speed, thereby increasing the suction capacity of the oil-gas separator. As the suction capacity of the oil-gas separator increases, the negative pressure inside the crankcase increases, so that air enters the crankcase through the first air supply pipeline 321, increasing the air delivery volume, achieving a reduction in the hydrogen concentration value while maintaining the internal pressure of the crankcase stable. As a result, the hydrogen concentration inside the crankcase is always within the safe range, and the hydrogen internal combustion engine operates stably.

[0012] In addition, the crankcase ventilation system of the present invention may also have the following additional technical features:

[0013] In some embodiments of the present invention, a one-way valve is provided on the first air supply pipeline, and the one-way valve is configured to open when the internal pressure of the crankcase is less than the internal pressure of the first air supply pipeline and the pressure difference between the internal pressure of the crankcase and the internal pressure of the first air supply pipeline is greater than a preset pressure difference.

[0014] In some embodiments of the present invention, a supercharger is provided on the intake pipeline, and the crankcase ventilation system further includes a second air supply pipeline, an inlet of the second air supply pipeline is connected to the supercharger, and an outlet of the second air supply pipeline is connected to a fourth connecting port of the crankcase.

[0015] In some embodiments of the present invention, the outlet of the second air supply pipeline is connected to the fourth connecting port of the crankcase through a flow limiting member, the flow limiting member has a flow limiting hole, the outlet of the second air supply pipeline is connected to the fourth connecting port of the crankcase through the flow limiting hole, and the flow limiting hole is used to limit the flow rate of air entering the crankcase.

[0016] The present invention also proposes a hydrogen internal combustion engine, which includes the crankcase ventilation system in the above embodiment.

[0017] The present invention also proposes a crankcase ventilation system control method, which is implemented based on the above crankcase ventilation system. The crankcase ventilation system control method includes:

[0018] Acquiring a hydrogen concentration value inside the crankcase through the hydrogen concentration detection unit;

[0019] The control unit executes a preset control logic according to the relationship between the hydrogen concentration value and a preset concentration value.

[0020] In addition, the crankcase ventilation system control method of the present invention may also have the following additional technical features:

[0021] In some embodiments of the present invention, executing the preset control logic includes:

[0022] When the hydrogen concentration value is greater than a first preset concentration value and less than or equal to a second preset concentration value, the control unit controls the oil-gas separator to increase its rotation speed according to a pulse duty cycle, wherein the second preset concentration value is greater than the first preset concentration value.

[0023] In some embodiments of the present invention, executing the preset control logic further includes:

[0024] In the cold start phase, the control unit controls the oil-gas separator to start in advance according to the hydrogen concentration value being greater than the first preset concentration value and less than or equal to the second preset concentration value.

[0025] In some embodiments of the present invention, executing the preset control logic further includes:

[0026] During the parking phase, the control unit controls the oil-gas separator to delay stopping according to the hydrogen concentration value being greater than the first preset concentration value and less than or equal to the second preset concentration value.

[0027] In some embodiments of the present invention, executing the preset control logic further includes:

[0028] Obtaining a change in hydrogen concentration inside the crankcase within a preset time;

[0029] Determining whether the hydrogen concentration inside the crankcase increases within the preset time and whether the increase is greater than a preset threshold;

[0030] According to the increase of the hydrogen concentration inside the crankcase within the preset time and the increase being greater than the preset threshold, the hydrogen injection is cut off and the machine is shut down for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference numerals are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0032] Figure 1 A schematic diagram of a partial structure of a crankcase ventilation system according to an embodiment of the present invention is schematically shown;

[0033] Figure 2 yes Figure 1 A partial enlarged view of point I in the middle;

[0034] Figure 3 Schematically shows a principle diagram of a crankcase ventilation system according to an embodiment of the present invention;

[0035] Figure 4 A first flow chart of a crankcase ventilation system control method according to an embodiment of the present invention is schematically shown;

[0036] Figure 5 A second flow chart schematically shows a method for controlling a crankcase ventilation system according to an embodiment of the present invention;

[0037] Figure 6 The relationship between the rotation speed and the pulse duty cycle of the oil-gas separator according to the embodiment of the present invention is schematically shown.

[0038] The reference numerals in the accompanying drawings represent the following:

[0039] 100, crankcase; 110, hydrogen concentration detection unit; 120, cylinder head cover; 200, oil-gas separator; 210, exhaust pipe; 300, air filter; 310, intake pipe; 321, first air supply pipe; 3211, one-way valve; 322, second air supply pipe; 3221, flow limiting component; 400, supercharger; 500, control unit. DETAILED DESCRIPTION

[0040] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0041] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0042] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0043] For ease of description, spatial relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, then the elements described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both above and below orientations.

[0044] Figure 1 A partial structural diagram of a crankcase ventilation system according to an embodiment of the present invention is schematically shown. Figure 2 yes Figure 1 A partial enlarged view of point I in the middle. Figure 3 The principle diagram of the crankcase ventilation system according to an embodiment of the present invention is schematically shown. Figures 1 to 3As shown, the present invention proposes a crankcase ventilation system, including a crankcase 100, an oil-gas separator 200, an air filter 300 and a control unit 500. A hydrogen concentration detection unit 110 is arranged inside the crankcase 100, an inlet of the oil-gas separator 200 is connected to a first connecting port of the crankcase 100, the air filter 300 is connected to a second connecting port of the crankcase 100 through an intake pipe 310, the air filter 300 can be selectively connected to a third connecting port of the crankcase 100 through a first air supply pipe 321, and the control unit 500 is signal-connected to the hydrogen concentration detection unit 110, the oil-gas separator 200 and the air filter 300.

[0045] By using the crankcase ventilation system in the present technical solution, the hydrogen concentration inside the crankcase 100 is detected by the hydrogen detection unit, and the control unit 500 controls the oil-gas separator 200 and the air filter 300 to work according to the hydrogen concentration value collected by the hydrogen detection unit. The air filter 300 is used to filter out dust and gravel in the air to ensure that the air entering the crankcase 100 is clean air. The oil-gas separator 200 can suck the exhaust gas in the crankcase 100, thereby changing the internal pressure of the crankcase 100. Specifically, when the hydrogen internal combustion engine is operating normally, the filtered air is transported through the intake pipe 310, and at the same time, the exhaust gas is sucked through the oil-gas separator 200. At this time, the hydrogen concentration is within the normal range, and the internal pressure of the crankcase 100 is stable. When the hydrogen internal combustion gas runs abnormally and the hydrogen concentration inside the crankcase 100 exceeds the safe range, the control unit 500 controls the oil-gas separator 200 to increase its speed, thereby increasing the suction capacity of the oil-gas separator 200. As the suction capacity of the oil-gas separator 200 increases, the negative pressure inside the crankcase 100 increases, and air enters the crankcase 100 through the first air supply pipeline 321, increasing the air delivery volume, achieving a reduction in the hydrogen concentration value while maintaining a stable internal pressure of the crankcase 100. As a result, the hydrogen concentration inside the crankcase 100 is always within a safe range, and the hydrogen internal combustion engine operates stably.

[0046] There are many reasons for hydrogen leakage, such as piston ring wear or abnormal deformation, cylinder scuffing due to poor lubrication (the inner wall of the cylinder is worn by the piston and piston ring to form deep grooves, resulting in friction and loss of sealing), low intake temperature during ignition or poor ignition leading to incomplete hydrogen combustion, etc. These situations may cause the hydrogen concentration to exceed the safe range, thereby causing explosions and other dangerous accidents. This technical solution can deal with hydrogen leakage in hydrogen internal combustion engines under various working conditions.

[0047] Optionally, the control unit 500 is an ECU (Electronic Control Unit), i.e., a vehicle-mounted control system. The control unit 500 includes a storage medium for the crankcase ventilation system control method. The storage medium may be a solid state drive, a flash memory, or other suitable storage device for long-term storage and calling of control logic and data of the hydrogen internal combustion engine.

[0048] Optionally, the hydrogen concentration detection unit 110 can be a hydrogen concentration sensor, which is arranged inside the crankcase 100, can detect the hydrogen concentration in real time, and feed back the detection result to the control unit 500, and then the control unit 500 controls the operation of each device according to the hydrogen concentration value to avoid the possibility of explosion in time.

[0049] Optionally, the oil-gas separator 200 is an active oil-gas separator, which can change the suction capacity of the crankcase by adjusting the rotational speed, that is, the higher the rotational speed, the greater the negative pressure of the crankcase, and the more oil and gas are extracted.

[0050] Further, since the control unit 500 can control the rotation speed of the oil-gas separator 200 to increase so as to increase the negative pressure of the crankcase 100, the first air-injection pipeline 321 can be set to connect or disconnect the oil-gas separator 200 and the crankcase 100 according to the pressure difference between the internal pressure of the crankcase 100 and the internal pressure of the first air-injection pipeline 321 to control the delivery amount of air. Specifically, when the internal pressure of the crankcase 100 is less than the internal pressure of the first air-injection pipeline 321 and the pressure difference between the internal pressure of the crankcase 100 and the internal pressure of the first air-injection pipeline 321 is greater than the preset pressure difference, the first air-injection pipeline 321 can connect the oil-gas separator 200 and the crankcase 100, so that air can be delivered through the first air-injection pipeline 321.

[0051] Furthermore, a one-way valve 3211 is provided on the first air supply pipeline 321, and the one-way valve 3211 is configured to open when the internal pressure of the crankcase 100 is lower than the internal pressure of the first air supply pipeline 321 and the pressure difference between the internal pressure of the crankcase 100 and the internal pressure of the first air supply pipeline 321 is greater than a preset pressure difference.

[0052] It can be understood that by setting the one-way valve 3211, the pipeline can be easily opened or closed, and the one-way valve 3211 can be connected or disconnected according to the pressure difference between the internal pressure of the crankcase 100 and the internal pressure of the first air supply pipeline 321, so that the one-way valve 3211 can play a role in various working conditions. For example, when the hydrogen combustion is insufficient due to low intake temperature or poor ignition, the hydrogen concentration in the crankcase 100 may be high. At this time, the control unit 500 controls the oil-gas separator 200 to increase the speed and increase the air extraction capacity. Due to the increase in air extraction capacity, the negative pressure inside the crankcase 100 increases. At this time, the one-way valve 3211 is opened, and air can enter the crankcase 100 through the first air supply pipeline 321, further diluting the hydrogen concentration, while maintaining the internal pressure of the crankcase 100 stable. For another example, when the engine is cold started, the hydrogen concentration in the crankcase 100 may be high. At this time, the control unit 500 controls the oil-gas separator 200 to start in advance, that is, before the combustion starts, the exhaust gas in the crankcase 100 is extracted in advance to reduce the pressure in the crankcase 100, and air is added to the crankcase 100 through the first air supply line 321 to accelerate the purging of hydrogen in the crankcase 100 and reduce the hydrogen concentration. For another example, when the engine is stopped, the hydrogen concentration in the crankcase 100 may be high. At this time, the control unit 500 controls the oil-gas separator 200 to stop later, that is, the oil-gas separator 200 is kept running for a short time after the combustion stops, so that the pressure in the crankcase 100 is reduced, and air is added to the crankcase 100 through the air supply line to accelerate the purging of hydrogen in the crankcase 100 and reduce the hydrogen concentration.

[0053] In the present technical solution, the preset pressure difference is 0.2Kpa, that is, when the internal pressure of the crankcase 100 is less than the internal pressure of the first air supply pipeline 321 and the pressure difference between the internal pressure of the crankcase 100 and the internal pressure of the first air supply pipeline 321 is greater than 0.2Kpa, the one-way valve 3211 is opened, the first air supply pipeline 321 and the crankcase 100 are connected, and the filtered air can enter the crankcase 100 through the first air supply pipeline 321; when the internal pressure of the crankcase 100 is less than the internal pressure of the first air supply pipeline 321 but the pressure difference is less than 0.2Kpa, or the internal pressure of the crankcase 100 is greater than the internal pressure of the first air supply pipeline 321, the one-way valve 321 is closed to prevent the air in the first air supply pipeline 321 from entering the crankcase 100 or to prevent the gas inside the crankcase 100 from flowing back. In other embodiments, the preset pressure difference may also be 0.1 Kpa, 0.15 Kpa or 0.25 Kpa, etc., which is set according to usage requirements and is not specifically limited here.

[0054] In the present technical solution, the one-way valve 3211 is a valve that can be automatically opened or closed according to the pressure difference, for example, a pneumatic diaphragm valve. In other embodiments, the one-way valve 3211 can also be connected to the control unit 500 by signal, and the control unit 500 controls the opening and closing according to the pressure difference between the internal pressure of the crankcase 100 and the internal pressure of the first air supply pipeline 321. Optionally, the one-way valve 3211 is connected to the cylinder head cover 120 by bolts, and the outlet of the first air supply pipeline 321 is connected to the one-way valve 3211.

[0055] Furthermore, a supercharger 400 is provided on the intake pipe 310 , and the crankcase ventilation system includes a second air supply pipe 322 , the inlet of the second air supply pipe 322 is connected to the supercharger 400 , and the outlet of the second air supply pipe 322 is connected to the fourth connecting port of the crankcase 100 .

[0056] It can be understood that the air before entering the crankcase 100 is first compressed by the supercharger 400 to increase the density of the air, so that more air is filled into the cylinder, thereby increasing the engine power. The supercharger 400 can increase the output power of the engine and improve the performance of the engine. When the engine is under a large load, under the action of the supercharger 400, the pressure of the supercharged air is relatively large, and the supercharged air will enter the interior of the crankcase 100 through the intake pipe 310 and the second air supply pipe 322, thereby reducing the hydrogen concentration inside the crankcase 100. When the hydrogen concentration inside the crankcase 100 is greater than the first preset concentration value under a large load condition, after the speed of the oil-gas separator 200 increases, air will be supplemented to the crankcase 100 through the first air supply pipe 321 and the second air supply pipe 322 at the same time.

[0057] Furthermore, the outlet of the second air supply pipeline 322 is connected to the fourth connecting port of the crankcase 100 through a flow limiting member 3221, and the flow limiting member 3221 has a flow limiting hole. The outlet of the second air supply pipeline 322 is connected to the fourth connecting port of the crankcase 100 through the flow limiting hole, and the flow limiting hole is used to limit the flow rate of air entering the crankcase 100.

[0058] By setting the flow-limiting hole, the amount of air entering the crankcase 100 can be limited to prevent the amount of air in the crankcase 100 from being too high. Optionally, the size of the flow-limiting hole is 1.5mm to 2.5mm. For example, the size of the flow-limiting hole can be 1.5mm, 2mm or 2.5mm, etc., which is set according to the specific use needs and is not specifically limited here. It can be understood that since the aperture of the flow-limiting hole is small, the amount of air entering the crankcase 100 can be limited, ensuring that under high load conditions, air can be supplemented through the second air supply pipeline 322, and at the same time, the amount of air entering the crankcase 100 is prevented from being too large. Optionally, the flow-limiting member 3221 can be a bolt with a hollow interior, and the flow-limiting hole is set on the bolt. The outlet of the second air supply pipeline 322 is connected to the bolt and is connected to the flow-limiting hole. The threaded portion of the bolt is threadedly connected to the cylinder head. It can be understood that the diameter of the high-load air supply pipe and the size of the flow-limiting hole are matched to play a role in limiting flow.

[0059] Furthermore, the oil-gas separator 200 is connected to the intake pipe 310 through the exhaust pipe 210, and the outlet of the exhaust pipe 210 is located between the supercharger 400 and the air filter 300. As described above, the oil-gas separator 200 can balance the pressure of the crankcase 100 by sucking the exhaust gas. In addition, the oil-gas separator 200 also has the function of separating the exhaust gas mixture. The gas separated by the oil-gas separator 200 is transported to the intake end of the supercharger 400 through the exhaust pipe 210 to participate in the combustion process.

[0060] Furthermore, the technical solution also provides a hydrogen internal combustion engine, including the above-mentioned crankcase ventilation system. The hydrogen internal combustion engine also includes a combustion chamber and a fuel injection device. Specifically, the combustion chamber is the core area where hydrogen fuel and air are mixed and combustion reaction is carried out, providing the power output of the internal combustion engine. The crankcase 100 is arranged below the combustion chamber. The fuel injection device includes at least one injector, and the injection port of the injector is connected to the combustion chamber, which is used to inject hydrogen into the combustion chamber for combustion reaction. The fuel injection device is connected to the control unit 500 by signal, and the control unit 500 controls the hydrogen injection amount and injection timing of the injector to ensure the combustion efficiency of the engine under various working conditions. When it is detected that the hydrogen concentration in the crankcase 100 exceeds the preset range, the control unit 500 can automatically adjust the speed of the oil-gas separator 200, or cut off the hydrogen injection and shut down when necessary to ensure the safe operation of the engine.

[0061] Further, Figure 4 A first flow chart of a crankcase ventilation system control method according to an embodiment of the present invention is schematically shown. Figure 4 The present technical solution also provides a crankcase ventilation system control method, which is implemented based on the above crankcase ventilation system. The crankcase ventilation system control method includes:

[0062] Obtaining the hydrogen concentration value inside the crankcase 100 through the hydrogen concentration detection unit 110;

[0063] The control unit 500 executes a preset control logic according to the relationship between the hydrogen concentration value and the preset concentration value.

[0064] According to the crankcase ventilation system control method of the technical solution, by obtaining the hydrogen concentration value in the crankcase 100 in real time, and executing the preset control logic according to whether the concentration value is within the preset safety range, the hydrogen concentration exceeding the standard accident caused by piston ring wear, abnormal deformation of piston ring, poor ignition and cylinder failure can be effectively prevented. Specifically, through the hydrogen internal combustion engine safety control method of the present invention, the continuous monitoring of the hydrogen concentration value in the crankcase 100 can be realized during the operation of the hydrogen internal combustion engine. When the hydrogen concentration value exceeds the safety range, the hydrogen internal combustion engine can automatically take appropriate protective measures, such as increasing the speed of the oil-gas separator 200 to connect the first air supply pipeline 321 and the crankcase 100, reducing or stopping the injection of hydrogen, and even shutting down for maintenance, so as to avoid safety accidents such as explosions caused by excessive hydrogen concentration values. The crankcase ventilation system control method not only improves the operating safety of the hydrogen fuel internal combustion engine, but also can extend the service life of the hydrogen internal combustion engine, reduce the economic losses caused by mechanical failures, and has significant industrial application value.

[0065] Further, Figure 5 A second flow chart of a crankcase ventilation system control method according to an embodiment of the present invention is schematically shown. Figure 5 , executing the preset control logic includes: when the hydrogen concentration value is greater than the first preset concentration value and less than or equal to the second preset concentration value, the control unit 500 controls the oil-gas separator 200 to increase the speed according to the pulse duty cycle, wherein the second preset concentration value is greater than the first preset concentration value.

[0066] That is, when the hydrogen concentration value is greater than the first preset concentration value and less than or equal to the second preset concentration value, the control unit 500 determines that the hydrogen concentration value in the crankcase 100 has exceeded the normal safety range but has not yet reached a dangerous level. At this time, the control unit 500 controls the speed of the oil-gas separator 200 to increase so as to increase the ability of the oil-gas separator 200 to suck exhaust gas, so that the internal pressure of the crankcase 100 is reduced, and the hydrogen concentration is also reduced. At the same time, when the internal pressure of the crankcase 100 is reduced to a value lower than the internal pressure of the first air supply pipeline 321 and the pressure difference exceeds the preset pressure, the one-way valve 3211 opens, and the air in the air filter 300 is supplemented to the inside of the crankcase 100 through the first air supply pipeline 321, so as to maintain the internal pressure of the crankcase 100 stable, and the hydrogen inside the crankcase 100 is further diluted.

[0067] Preferably, Figure 6 The relationship between the rotation speed and the pulse duty ratio of the oil-gas separator 200 according to the embodiment of the present invention is schematically shown. Figure 6 As shown, the control unit 500 controls the rotation speed of the oil-gas separator 200 according to the pulse duty ratio (the proportion of the high level in one pulse cycle). For example, when the hydrogen concentration value is greater than the first preset concentration value and less than or equal to the second preset concentration value, if the pulse duty ratio is between 85% and 90%, the rotation speed of the oil-gas separator 200 is increased to 11000rpm.

[0068] In the present technical solution, the first preset concentration value is 20000ppm (2%), and the second preset concentration value is 35000ppm. That is, when the hydrogen concentration value is lower than 20000ppm, the control unit 500 determines that the hydrogen concentration value in the crankcase 100 is in a safe state, and the engine maintains normal operation without taking any measures; when the hydrogen concentration is higher than 20000ppm but less than or equal to 35000ppm, the control unit 500 determines that the hydrogen concentration value in the crankcase 100 exceeds the normal safety range but has not yet reached the dangerous level, and the control unit 500 controls the oil-gas separator 200 to increase the speed, and at the same time, replenishes air to the crankcase 100 through the first air supply pipeline 321. If the hydrogen concentration inside the crankcase 100 continues to increase to more than 35000ppm after the speed of the oil-gas separator 200 increases, it means that the hydrogen concentration has entered the dangerous range. At this time, it is necessary to immediately cut off the hydrogen injection, and at the same time trigger the shutdown procedure of the hydrogen internal combustion engine to force the engine to stop running to avoid any further danger. In the present technical solution, in other embodiments, in other embodiments, the first preset concentration value may also be 25000ppm, 28000ppm or 30000ppm, etc., and the second preset concentration value may also be 34000ppm, 36000ppm or 37000ppm, etc., which are set according to the needs of use and are not specifically limited here.

[0069] Continue to see Figure 5 In some embodiments, executing the preset control logic also includes: obtaining the change in hydrogen concentration inside the crankcase 100 within a preset time; determining whether the hydrogen concentration inside the crankcase 100 increases within a preset time and whether the increase is greater than a preset threshold; according to the increase in the hydrogen concentration inside the crankcase 100 within a preset time and the increase is greater than a preset threshold, cutting off the hydrogen injection and shutting down for maintenance.

[0070] It is understandable that if the hydrogen concentration inside the crankcase 100 increases in a short period of time, and the hydrogen concentration increment is greater than the preset threshold value, it means that the hydrogen concentration rises rapidly in a short period of time, which indicates that there may be a rapid and large amount of hydrogen leakage. Even if the hydrogen concentration value may be within the safe range (for example, less than 20000ppm), this mutation still indicates that a serious fault may have occurred in the hydrogen internal combustion engine. In the above case, the control device will immediately cut off the hydrogen injection and perform a shutdown operation to prevent further hydrogen leakage or combustion. At the same time, the control device controls the alarm to sound an alarm, prompting that emergency maintenance is required to find and repair the fault that causes the rapid increase in hydrogen concentration. This embodiment enhances the safety control capability of the system during the operation of the hydrogen internal combustion engine by introducing the monitoring of the trend of hydrogen concentration changes. Specifically, this embodiment not only focuses on whether the hydrogen concentration value is within the safe range, but also attaches importance to the rate of change of the concentration value in a short period of time. Even if the hydrogen concentration is within the safe range during the initial detection, if the concentration value rises rapidly in a short period of time, this usually indicates that there may be a more serious fault inside the system, such as piston ring damage or other problems that cause a large amount of hydrogen leakage. By implementing this more rigorous detection and response mechanism, the control device can promptly identify and handle abnormal changes in hydrogen concentration, effectively avoiding explosions or other safety accidents caused by rapid accumulation of hydrogen. This solution significantly improves the safety and reliability of hydrogen internal combustion engines, especially in response to sudden leakage events, ensuring that the engine can be shut down quickly and safely, preventing the fault from further deteriorating, and protecting the safety of equipment and personnel.

[0071] Optionally, the preset time can be within 2s-3s, and the preset threshold is 5000ppm. First, setting a time interval of 2-3 seconds enables the system to detect changes in hydrogen concentration in almost real time. Hydrogen is a very flammable and dangerous gas, especially in hydrogen internal combustion engines, and its explosion limit range is wide. Therefore, obtaining the hydrogen concentration increment in a short time (2-3 seconds) can timely capture the sharp rise in concentration caused by leakage or other faults, so as to quickly take countermeasures to prevent accidents. Secondly, selecting 5000ppm as the preset threshold of concentration change can ensure that the system has sufficient detection accuracy for sensitive changes in hydrogen concentration. The setting of this value takes into account the potential danger of hydrogen and the concentration fluctuation range in the normal operation of the internal combustion engine. In general, the detection of an increase in hydrogen concentration of more than 5000ppm within 2-3 seconds indicates that there may be significant hydrogen leakage inside the hydrogen internal combustion engine. This rapid and large concentration change is usually a harbinger of major failures. By setting this time and threshold, the control device can quickly make a judgment, cut off the hydrogen injection and shut down, and prevent explosions or other major safety accidents caused by excessive concentration.

[0072] Furthermore, executing the preset control logic also includes: in the cold start stage, the control unit 500 controls the oil-gas separator 200 to start in advance according to the hydrogen concentration value being greater than the first preset concentration value and less than or equal to the second preset concentration value.

[0073] It is understandable that by controlling the oil-gas separator 200 to start before the engine is ignited, the exhaust gas inside the crankcase 100 can be sucked in advance, so that the hydrogen concentration inside the crankcase 100 is reduced, and the hydrogen concentration is prevented from being too high during ignition. During this period, due to the early start of the oil-gas separator 200, the air pressure inside the crankcase 100 is reduced. If the pressure inside the crankcase 100 is lower than the pressure of the first intake pipeline 310 and exceeds 0.2Kpa, the one-way valve 3211 opens, and air is supplemented to the inside of the crankcase 100 through the first intake pipeline 310, further diluting the hydrogen concentration. It is understandable that when it is detected that the hydrogen concentration value is greater than the first preset concentration value but less than or equal to the second preset concentration value, the oil-gas separator 200 is started in advance to ensure that the hydrogen concentration is within a safe range; when the hydrogen concentration value is less than the first preset concentration value, there is no need to start the oil-gas separator 200 in advance, thereby saving energy; when the hydrogen concentration value is greater than the second preset concentration value, the engine is shut down for maintenance.

[0074] Furthermore, executing the preset control logic also includes: in the parking stage, the control unit 500 controls the oil-gas separator 200 to delay stopping according to the hydrogen concentration value being greater than the first preset concentration value and less than or equal to the second preset concentration value.

[0075] Specifically, during the parking stage, if the hydrogen concentration value is greater than the first preset concentration value and less than or equal to the second preset concentration value, after the engine is turned off, the control unit 500 controls the oil-gas separator 200 to continue to operate for a period of time until the hydrogen concentration value is less than the first preset concentration value. During this period, due to the delayed stop of the oil-gas separator 200, the air pressure inside the crankcase 100 decreases. If the pressure inside the crankcase 100 is lower than the pressure of the first intake pipe 310 and exceeds 0.2Kpa, the one-way valve 3211 opens, and air is added to the interior of the crankcase 100 through the first intake pipe 310, further diluting the hydrogen concentration. During the parking stage, if the hydrogen concentration value is less than the first preset concentration value, the oil-gas separator 200 does not need to be delayed; if the hydrogen concentration value is greater than the second preset concentration value, it is necessary to shut down for inspection.

[0076] When the crankcase ventilation system control method provided by the technical solution is adopted, the working process of the crankcase ventilation system at least includes the following embodiments:

[0077] Embodiment 1: The hydrogen concentration detection unit 110 detects that the hydrogen concentration value inside the crankcase 100 is less than or equal to 20000 ppm.

[0078] At this time, the control unit 500 determines that the hydrogen concentration is within a safe range. The oil-gas separator 200 maintains a normal speed without additional adjustment operations, the intake pipe 310 normally inhales air, and the fuel injection device and other engine components remain in normal working conditions. In addition, the hydrogen concentration detection unit 110 continues to monitor the hydrogen concentration in real time to ensure that it is stable within a safe range. If there is a change, the control unit 500 will take further control measures based on the change in hydrogen concentration.

[0079] Embodiment 2: The hydrogen concentration detection unit 110 detects that the hydrogen concentration value in the crankcase 100 is greater than 20000 ppm.

[0080] At this time, the control unit 500 determines that the hydrogen concentration exceeds the normal safety range. The control unit 500 controls the speed of the oil-gas separator 200 to increase according to the pulse duty cycle. As the speed of the oil-gas separator 200 increases, the air pressure in the crankcase 100 decreases, so that the one-way valve 3211 opens, and air is replenished to the crankcase 100 through the low-load air supply system, and the intake pipe 310 intakes air normally. At this time, the discharge of hydrogen increases, and at the same time, the intake of air increases. Therefore, the pressure of the crankcase 100 remains stable, but the concentration of hydrogen decreases. After adjusting the speed of the oil-gas separator 200, the control unit 500 continues to monitor the hydrogen concentration to ensure that it drops within a safe range.

[0081] Example 3: Based on Example 2, the hydrogen concentration continues to rise to greater than 35000 ppm.

[0082] At this time, the control unit 500 determines that the hydrogen concentration has reached a dangerous level. The control unit 500 controls the injector to stop hydrogen injection to prevent more hydrogen from entering the combustion chamber; the control unit 500 triggers the engine to shut down and force the engine to stop running to avoid further safety risks; the control unit 500 controls the alarm to sound an alarm to notify the operator to perform emergency maintenance to find and repair the fault that caused the abnormal increase in hydrogen concentration.

[0083] Example 4: Based on Example 2, the hydrogen concentration continues to drop below 20,000 ppm.

[0084] At this time, the control unit 500 determines that the hydrogen concentration has returned to a safe range. The control unit 500 controls the speed of the oil-gas separator 200 to gradually decrease to restore to a normal working state. As the speed of the oil-gas separator 200 decreases, the internal pressure of the crankcase 100 gradually increases, and the pressure difference between the internal pressure of the crankcase 100 and the internal pressure of the first air supply pipeline 321 gradually decreases, the one-way valve 3211 closes, and the first air supply pipeline 321 stops replenishing air to the crankcase 100. In the process of reducing the speed, the control unit 500 continues to monitor the hydrogen concentration to ensure that it is stable within a safe range. If there is any change, the control unit 500 will make adjustments again.

[0085] Embodiment 5: The control unit 500 detects that the hydrogen concentration value increases within 2 seconds, and the change in hydrogen concentration exceeds 5000 ppm.

[0086] In this case, no matter which interval the hydrogen concentration value is in, the control unit 500 will control the injector to immediately stop hydrogen injection to prevent further leakage of hydrogen.

[0087] Embodiment 6: The engine is under a relatively large load, the supercharger 400 operates normally, and the internal pressure of the crankcase 100 is greater than the internal pressure of the first air supply line 321 .

[0088] In this case, the air pressure passing through the supercharger 400 is relatively high, and the air enters the crankcase 100 through the second air supply pipeline 322 and the flow limiting hole, reducing the hydrogen concentration in the crankcase 100; the one-way valve 3211 is in a closed state to prevent gas backflow due to the internal pressure of the crankcase 100 being higher than the internal pressure of the first air supply pipeline 321.

[0089] Embodiment 7: During the cold start phase, the hydrogen concentration value is greater than 20000 ppm and less than or equal to 35000 ppm.

[0090] At this time, the control unit 500 controls the oil-gas separator 200 to start in advance. Due to the early start of the oil-gas separator 200, the air pressure inside the crankcase 100 is reduced to a level lower than the pressure of the first intake pipe 310, and the pressure difference between the internal pressure of the crankcase 100 and the internal pressure of the first air supply pipe 321 exceeds 0.2 Kpa, so that the one-way valve 3211 is opened, and air is supplemented into the crankcase 100 through the first intake pipe 310, so that the hydrogen concentration value is reduced to below 20000 ppm.

[0091] Embodiment 8: During the parking phase, the hydrogen concentration is greater than 20,000 ppm and less than or equal to 35,000 ppm.

[0092] At this time, the oil-gas separator 200 is controlled to stop after a delay. Due to the delayed stop of the oil-gas separator 200, the air pressure inside the crankcase 100 is reduced to a pressure lower than the pressure of the first intake pipe 310 and the pressure difference exceeds 0.2 Kpa, so that the one-way valve 3211 is opened, and air is replenished into the crankcase 100 through the first intake pipe 310, so that the hydrogen concentration value is reduced to below 20000 ppm.

[0093] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A crankcase ventilation system, characterized in that: include: A crankcase (100), wherein a hydrogen concentration detection unit (110) is arranged inside the crankcase (100); An oil-gas separator (200), wherein an inlet of the oil-gas separator (200) is in communication with a first communication port of the crankcase (100); An air filter (300), the air filter (300) being in communication with the second communication port of the crankcase (100) via an air intake pipeline (310), and the air filter (300) being selectively in communication with the third communication port of the crankcase (100) via a first air supply pipeline (321); A control unit (500) is signal-connected to the hydrogen concentration detection unit (110), the oil-gas separator (200) and the air filter (300).

2. The crankcase ventilation system according to claim 1, characterized in that A one-way valve (3211) is provided on the first air supply pipeline (321), and the one-way valve (3211) is configured to open when the internal pressure of the crankcase (100) is lower than the internal pressure of the first air supply pipeline (321) and the pressure difference between the internal pressure of the crankcase (100) and the internal pressure of the first air supply pipeline (321) is greater than a preset pressure difference.

3. The crankcase ventilation system according to claim 1, characterized in that: A supercharger (400) is provided on the intake pipe (310), and the crankcase ventilation system further comprises a second air supply pipe (322), an inlet of the second air supply pipe (322) is connected to the supercharger (400), and an outlet of the second air supply pipe (322) is connected to a fourth connecting port of the crankcase (100).

4. The crankcase ventilation system according to claim 3, characterized in that The outlet of the second air supply pipeline (322) is connected to the fourth connecting port of the crankcase (100) via a flow limiting component (3221), and the flow limiting component (3221) has a flow limiting hole. The outlet of the second air supply pipeline (322) is connected to the fourth connecting port of the crankcase (100) via the flow limiting hole, and the flow limiting hole is used to limit the flow rate of air entering the crankcase (100).

5. A hydrogen internal combustion engine, characterized in that: Comprising a crankcase ventilation system as claimed in any one of claims 1 to 4.

6. A crankcase ventilation system control method, characterized in that: Based on the crankcase ventilation system according to any one of claims 1 to 4, it is characterized in that the crankcase ventilation system control method comprises: Acquiring a hydrogen concentration value inside the crankcase (100) through the hydrogen concentration detection unit (110); The control unit (500) executes a preset control logic according to the relationship between the hydrogen concentration value and a preset concentration value.

7. The crankcase ventilation system control method according to claim 6, characterized in that: The execution of the preset control logic includes: When the hydrogen concentration value is greater than a first preset concentration value and less than or equal to a second preset concentration value, the control unit (500) controls the speed of the oil-gas separator (200) to increase according to a pulse duty cycle, wherein the second preset concentration value is greater than the first preset concentration value.

8. The crankcase ventilation system control method according to claim 7, characterized in that: The execution of the preset control logic also includes: In the cold start phase, the control unit (500) controls the oil-gas separator (200) to start in advance according to the hydrogen concentration value being greater than the first preset concentration value and less than or equal to the second preset concentration value.

9. The crankcase ventilation system control method according to claim 7, characterized in that: The execution of the preset control logic also includes: During the parking phase, the control unit (500) controls the oil-gas separator (200) to delay stopping according to the hydrogen concentration value being greater than the first preset concentration value and less than or equal to the second preset concentration value.

10. The crankcase ventilation system control method according to claim 6, characterized in that: The execution of the preset control logic also includes: Acquiring a change in the hydrogen concentration inside the crankcase (100) within a preset time; Determining whether the hydrogen concentration inside the crankcase (100) increases within the preset time and whether the increase is greater than a preset threshold; According to the increase in the hydrogen concentration inside the crankcase (100) within the preset time and the increase being greater than the preset threshold, the hydrogen injection is cut off and the machine is shut down for maintenance.

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