Crankcase ventilation system and vehicle

Abstract

The utility model provides a crankcase ventilation system and a vehicle. The crankcase ventilation system comprises an air cylinder body and a crankcase which are connected up and down. The air inlet unit and the exhaust unit are respectively communicated with the air cylinder body, and the exhaust unit comprises a three-way catalyst; the crankcase communicates with the air inlet unit through an air supplementing pipeline. The gas inlet end of the oil-gas separation unit is communicated with the crankcase, and the gas outlet end of the oil-gas separation unit is communicated with the gas inlet unit or the three-way catalyst of the gas outlet unit. According to the arrangement of the gas supplementing pipeline and the trend design of the gas at the exhaust end of the oil-gas separation unit, hydrogen in the crankcase can be actively swept away so that the hydrogen concentration can be controlled within a reasonable range, and the ventilation effect of the crankcase can be guaranteed.

Description

Technical Field

[0001] The present application relates to the technical field of engines, and particularly to a crankcase ventilation system and a vehicle. Background Art

[0002] During the operation of a hydrogen engine, hydrogen ejected from a nozzle mixes with fresh air input from an intake manifold inside a cylinder block. This mixture of gases can leak into the crankcase through the gap between the piston and the cylinder wall. Since there is engine oil in the gap between the piston and the cylinder wall, the hydrogen and air that leak into the crankcase will also mix with the oil vapor of the engine oil to form a mixed oil-gas mixture. The concentration limit for hydrogen explosion is between 4% and 76%, and the hydrogen concentration in the mixed oil-gas mixture may reach more than 10%, presenting an explosion risk. Therefore, it is necessary to correspondingly adjust the structure of the crankcase ventilation system of the hydrogen engine to dilute and reduce the hydrogen concentration in the mixed oil-gas mixture in the crankcase, and to reasonably design the destination of the diluted mixed oil-gas mixture to improve the ventilation effect of the crankcase. Utility Model Content

[0003] In view of this, the purpose of the present application is to provide a crankcase ventilation system and a vehicle to dilute and reduce the hydrogen concentration in the mixed oil-gas mixture in the crankcase, and to reasonably plan the destination of the diluted mixed oil-gas mixture to improve the ventilation effect of the crankcase.

[0004] Based on the above purpose, the present application provides a crankcase ventilation system, including:

[0005] A cylinder block and a crankcase connected up and down;

[0006] An intake unit and an exhaust unit, respectively communicating with the cylinder block, the exhaust unit including a three-way catalytic converter; the crankcase communicates with the intake unit through a make-up gas pipeline;

[0007] An oil-gas separation unit, its intake end communicating with the crankcase, and its exhaust end communicating with the intake unit or the three-way catalytic converter of the exhaust unit.

[0008] Further, it further includes a tail-sweeping main pipeline, a first branch pipeline, and a second branch pipeline. The exhaust end of the oil-gas separation unit communicates with the tail-sweeping main pipeline. The first branch pipeline communicates with the intake unit, and the second branch pipeline communicates with the three-way catalytic converter of the exhaust unit. A tail-sweeping valve is provided on the tail-sweeping main pipeline, and the tail-sweeping valve is used to make the tail-sweeping main pipeline communicate with the first branch pipeline or the second branch pipeline.

[0009] Further, the intake unit includes a compressor, an intercooler, a throttle valve, and an intake manifold connected in sequence;

[0010] The intake manifold communicates with the cylinder block;

[0011] The intake end of the air supplement pipeline is located between the intercooler and the throttle valve;

[0012] The first branch pipeline is communicated with the intake end of the compressor.

[0013] Further, the exhaust unit includes an exhaust manifold, a turbine and the three-way catalytic converter which are connected in sequence;

[0014] The exhaust manifold is communicated with the cylinder block;

[0015] The exhaust end of the second branch pipeline is located between the turbine and the three-way catalytic converter.

[0016] Further, it further includes a cylinder head and a blow-by pipeline. The cylinder head is located at the top of the cylinder block. An air supplement port is provided at the lower part of the crankcase, and the air supplement port is communicated with the air supplement pipeline; One end of the blow-by pipeline is communicated with the upper part of the crankcase, and the other end is communicated with the oil-gas separation unit.

[0017] Further, the oil-gas separation unit includes a first oil-gas separator and the second oil-gas separator which are connected; The intake end of the first oil-gas separator is communicated with the crankcase, the outlet end of the first oil-gas separator is communicated with the intake end of the second oil-gas separator, and the exhaust end of the second oil-gas separator is communicated with the intake unit or the three-way catalytic converter of the exhaust unit.

[0018] Further, at least part of the first oil-gas separator is located inside the cylinder head, and the second oil-gas separator is located outside the cylinder head.

[0019] Further, the first oil-gas separator is a labyrinth separator, and the second oil-gas separator is a centrifugal separator.

[0020] Further, both the first oil-gas separator and the second oil-gas separator are provided with oil outlet ports, and the oil outlet ports are communicated with the crankcase.

[0021] Based on the same inventive concept, the present disclosure also provides a vehicle, and the vehicle includes the crankcase ventilation system as described in any one of the above.

[0022] As can be seen from the above, the crankcase ventilation system and vehicle provided by the present application include a cylinder block, a crankcase, an intake unit, an exhaust unit, and an oil-gas separation unit. The intake unit and the exhaust unit are respectively connected to the cylinder block, and the exhaust unit further includes a three-way catalytic converter. The intake end of the oil-gas separation unit is connected to the crankcase, and its exhaust end is connected to the three-way catalytic converter of the intake unit or the exhaust unit. Among them, the setting of the make-up gas pipeline can be used to connect the crankcase and the intake pipeline, that is, the fresh air in the intake unit can enter the crankcase through the make-up gas pipeline, which can effectively reduce the concentration of hydrogen in the mixed oil-gas in the crankcase and avoid the explosion risk. In order to quickly discharge the hydrogen in the crankcase, the present application also reasonably plans the subsequent flow direction of the mixed oil-gas discharged from the crankcase, that is, the exhaust end of the oil-gas separation unit can be connected to the intake unit or the three-way catalytic converter of the exhaust unit, that is, the conduction direction can be set based on the temperature of the three-way catalytic converter. In addition, the two conduction directions can also be used as backups for each other. Once a certain conduction direction is blocked, the gas can be discharged through the other conduction direction. The above settings of the make-up gas pipeline and the design of the flow direction of the gas at the exhaust end of the oil-gas separation unit can not only actively sweep the hydrogen in the crankcase to control the hydrogen concentration within a reasonable range, but also ensure the ventilation effect of the crankcase. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the present application or related technologies, the following will briefly introduce the drawings required for use in the description of the embodiments or related technologies. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 FIG. is a schematic structural diagram of a crankcase ventilation system according to an embodiment of the present application in the main view direction;

[0025] Figure 2 FIG. is a schematic structural diagram of a crankcase ventilation system according to an embodiment of the present application in the top view direction.

[0026] In the figure: 1, cylinder head; 2, cylinder block; 3, crankcase; 4, intake unit; 41, compressor, 42, intercooler, 43, throttle valve; 44, intake manifold; 5, exhaust unit; 51, exhaust manifold; 52, turbine; 53, three-way catalytic converter; 6, oil-gas separation unit; 61, first oil-gas separator; 62, second oil-gas separator; 7, make-up gas pipeline; 71, make-up gas valve; 8, blow-by gas pipeline; 9, tail-sweeping pipeline; 91, tail-sweeping main pipeline; 92, first branch pipeline; 93, second branch pipeline; 94, tail-sweeping valve. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] To make the objectives, technical solutions and advantages of the present application clearer and more understandable, the present application will be further described in detail below with reference to specific embodiments and the accompanying drawings.

[0028] It should be noted that unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present application should have the ordinary meanings understood by those of ordinary skill in the field to which the present application belongs. The "first", "second" and similar terms used in the embodiments of the present application do not denote any order, quantity or importance, but are only used to distinguish different components. The terms such as "include" or "comprise" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The terms such as "connect" or "couple" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The terms such as "upper", "lower", "left" and "right" are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0029] As described in the background art, during the operation of a hydrogen engine, the hydrogen ejected from the jet nozzle mixes with the fresh air input from the intake manifold inside the cylinder block. This mixture of gases can leak into the crankcase through the gap between the piston and the cylinder wall. Since there is engine oil in the gap between the piston and the cylinder wall, the hydrogen and air that leak into the crankcase will also mix with the oil vapor of the engine oil to form a mixed oil-gas mixture. The concentration limit for hydrogen explosion is between 4% and 76%, and the hydrogen concentration in the mixed oil-gas mixture that leaks into the crankcase may reach more than 10%, presenting an explosion risk. Therefore, it is necessary to improve the ventilation effect of the crankcase.

[0030] The applicant has found that fresh air in the intake unit can be introduced into the crankcase, that is, the crankcase is supplemented with air, so that the hydrogen concentration in the mixed oil-gas mixture in the crankcase is maintained below 4%. However, supplementing air to the crankcase will inevitably cause a change in the pressure of the crankcase. If the pressure of the crankcase is too high, it will affect the normal operation of the crankshaft. Therefore, in order to balance the pressure in the crankcase and remove the hydrogen in the crankcase as soon as possible, the diluted air in the crankcase is subjected to oil-gas separation treatment, and the gas after the oil-gas separation treatment is returned to the intake manifold, so that the treated gas can be combusted again. However, the gas components after the oil-gas separation are mainly air and hydrogen, and the temperature of this air and hydrogen is relatively high and in a semi-combustion state, with relatively high energy. If the gas after the oil-gas separation is only returned to the intake manifold, the energy is not utilized, resulting in energy waste.

[0031] On the other hand, hydrogen engines operate in lean burn mode and require a mixture with an excess air coefficient greater than 2. When this mixture enters the engine, it results in a high oxygen content in the cylinder. Additionally, the cylinder temperature is relatively high during the combustion process, leading to the generation of NOx (nitrogen oxides). Therefore, the main pollutant produced during hydrogen combustion is NOx. Taking a turbocharged hydrogen engine as an example, the NOx emissions can even reach 7000 ppm. In addition, a small amount of lubricating oil enters the cylinder and burns to form HC (hydrocarbons) and CO. Generally, a three-way catalytic converter can be used to convert CO, HC, and NOx in the hydrogen engine exhaust into harmless carbon dioxide, water, and nitrogen. However, the effective operating temperature range of the three-way catalytic converter is 250 - 350 °C. Temperatures that are too high or too low may affect the performance of the three-way catalytic converter, even causing catalyst failure or exceeding the exhaust emission standards. For a cold-start engine, it is difficult for the three-way catalytic converter to reach its effective operating temperature during the initial stage of engine startup. Therefore, there will be a phenomenon of exceeding the exhaust emission standards during this stage.

[0032] The applicant has found that the energy of the gas after oil-gas separation described above can be utilized. That is, during the cold-start stage of the engine, the gas after oil-gas separation is introduced into the three-way catalytic converter to heat the three-way catalytic converter. Moreover, the hydrogen in the gas after oil-gas separation can also oxidize CO, HC, and NOx in the engine exhaust at the three-way catalytic converter to be converted into harmless carbon dioxide, water, and nitrogen. The heat released during this process enables the three-way catalyst to quickly heat up and can reduce the exhaust emissions during the cold start of the engine.

[0033] The following will be combined with the attached Figure 1-2 to illustrate the embodiments of the present application.

[0034] In some embodiments, a crankcase ventilation system includes:

[0035] A cylinder block 2 and a crankcase 3 connected up and down;

[0036] An intake unit 4 and an exhaust unit 5, which are respectively communicated with the cylinder block 2. The exhaust unit 5 includes a three-way catalytic converter 53; the crankcase 3 is communicated with the intake unit 4 through a make-up gas pipeline 7;

[0037] An oil-gas separation unit 6, whose intake end is communicated with the crankcase 3, and whose exhaust end is communicated with the intake unit 4 or the three-way catalytic converter 53 of the exhaust unit 5.

[0038] It should be noted that the hydrogen engine includes a cylinder head 1, a cylinder block 2, and a crankcase 3 arranged from top to bottom. The main function of the intake unit 4 is to introduce external air into the cylinder block 2, mix it with hydrogen to form a combustible mixture, and then distribute it to each cylinder in the cylinder block 2. The exhaust unit 5 is used to collect the exhaust gas discharged from each cylinder and discharge it into the atmosphere after treatment (such as treatment by a three-way catalytic converter 53). In addition, the intake unit 4 and the exhaust unit 5 can be fixed to the cylinder block 2 or the cylinder head 1 with studs. However, whether it is fixed to the cylinder block 2 or the cylinder head 1, it is connected to the cylinder block 2, or specifically to each cylinder in the cylinder block 2, to supply air to each cylinder.

[0039] Among them, the make-up gas pipeline 7 is used to connect the intake unit 4 and the crankcase 3, that is, the fresh air of the intake unit 4 can be supplemented into the crankcase 3 to dilute the hydrogen concentration in the crankcase 3. A make-up gas valve 71 can be provided on the make-up gas pipeline 7. The make-up gas valve 71 is a one-way valve, and its opening degree can be set according to the hydrogen concentration in the crankcase 3. That is, when the hydrogen concentration in the crankcase 3 is higher than 4%, to avoid the explosion risk, the make-up gas valve 71 opens, and its opening degree increases with the increase of the hydrogen concentration, or decreases with the decrease of the hydrogen concentration. That is, the setting of the make-up gas pipeline 7 can control the hydrogen concentration in the crankcase 3 below 4% to avoid the explosion risk.

[0040] Among them, the oil-gas separation unit 6 can be an oil-gas separator. The intake end of the oil-gas separation unit 6 is connected to the crankcase 3, that is, the mixed oil and gas in the crankcase 3 flows into the oil-gas separator after being diluted by fresh air to re-separate the oil in the mixed oil and gas, improve the recovery rate of the oil, and reduce the oil and gas components in the exhaust gas. The exhaust end of the oil-gas separation unit 6 can be connected to the three-way catalytic converter 53 of the intake unit 4 or the exhaust unit 5. The main components of the gas at the exhaust end of the oil-gas separation unit 6 are a mixture of air and hydrogen. This mixture has a higher temperature and certain energy. Specifically, when the temperature of the three-way catalytic converter 53 is higher than its effective temperature, the exhaust end of the oil-gas separation unit 6 is connected to the intake unit 4 so that the mixture directly enters the intake unit 4 and then enters the cylinder block 2 for secondary combustion; alternatively, when the temperature of the three-way catalytic converter 53 is lower than its effective temperature, the exhaust end of the oil-gas separation unit 6 is connected to the three-way catalytic converter 53 of the exhaust unit 5 so that the hydrogen in the mixture with certain energy undergoes an oxidation reaction at the three-way catalyst to convert CO, HC, and NOx in the engine exhaust gas into harmless carbon dioxide, water, and nitrogen. The heat released in this process causes the three-way catalyst to quickly heat up and can reduce the exhaust emissions during cold start of the engine.

[0041] The crankcase ventilation system provided in this embodiment includes a cylinder block 2, a crankcase 3, an intake unit 4, an exhaust unit 5, and an oil-gas separation unit 6. The intake unit 4 and the exhaust unit 5 are respectively connected to the cylinder block 2, and the exhaust unit 5 further includes a three-way catalyst 53. The intake end of the oil-gas separation unit 6 is connected to the crankcase 3, and its exhaust end is connected to the three-way catalyst 53 of the intake unit 4 or the exhaust unit 5. Among them, the setting of the make-up gas pipeline 7 can be used to connect the crankcase 3 and the intake pipeline, that is, the fresh air in the intake unit 4 can enter the crankcase 3 through the make-up gas pipeline 7, which can effectively reduce the concentration of hydrogen in the mixed oil and gas in the crankcase 3 and avoid the explosion risk. To quickly discharge the hydrogen in the crankcase 3, this embodiment also reasonably plans the subsequent flow direction of the mixed oil and gas discharged from the crankcase 3, that is, the exhaust end of the oil-gas separation unit 6 can be connected to the intake unit 4 or the three-way catalyst 53 of the exhaust unit 5, that is, the conduction direction can be set based on the temperature of the three-way catalyst 53. In addition, the two conduction directions can also be used as backups for each other. Once one conduction direction is blocked, the gas can be discharged through the other conduction direction. The above setting of the make-up gas pipeline 7 and the design of the flow direction of the gas at the exhaust end of the oil-gas separation unit 6 can not only actively sweep the hydrogen in the crankcase 3 to control the hydrogen concentration within a reasonable range, but also ensure the ventilation effect of the crankcase 3.

[0042] In some embodiments, the crankcase ventilation system further includes a tail-sweeping pipeline 9. The tail-sweeping pipeline 9 includes a tail-sweeping main pipeline 91, a first branch pipeline 92, and a second branch pipeline 93. The exhaust end of the oil-gas separation unit 6 is connected to the tail-sweeping main pipeline 91. The first branch pipeline 92 is connected to the intake unit 4, and the second branch pipeline 93 is connected to the three-way catalyst 53 of the exhaust unit 5. A tail-sweeping valve 94 is provided on the tail-sweeping main pipeline 91 to make the tail-sweeping main pipeline 91 communicate with the first branch pipeline 92 or the second branch pipeline 93.

[0043] Among them, the tail-sweeping valve 94 is a three-way valve.

[0044] This embodiment further describes the specific implementation manner of connecting the exhaust end of the oil-gas separation unit to the three-way catalytic converter 53 of the exhaust unit 5 or to the intake unit 4. That is, a tail-sweeping main pipeline 91, a first branch pipeline 92, and a second branch pipeline 93 are provided, and a tail-sweeping valve 94 is provided on the tail-sweeping main pipeline 91. Specifically, when the temperature of the three-way catalytic converter 53 is higher than its effective operating temperature, the tail-sweeping valve 94 conducts the tail-sweeping main pipeline 91 and the first branch pipeline 92 to connect the exhaust end of the oil-gas separation unit 6 to the intake unit 4; when the temperature of the three-way catalytic converter 53 is less than or equal to its effective operating temperature, the tail-sweeping valve 94 conducts the tail-sweeping main pipeline 91 and the second branch pipeline 93 to connect the exhaust end of the oil-gas separation unit 6 to the three-way catalytic converter 53 of the exhaust unit 5. The above implementation has a simple pipeline setting, and the setting of the tail-sweeping valve 94 can quickly switch the connection state between the exhaust end of the oil-gas separation unit 6 and the intake unit 4 or the three-way catalytic converter 53 of the exhaust unit 5, which is beneficial to the rapid discharge of hydrogen in the crankcase 3 and improves the ventilation effect of the crankcase 3.

[0045] In some embodiments, the intake unit 4 includes a compressor 41, an intercooler 42, a throttle valve 43, and an intake manifold 44 connected in sequence;

[0046] The intake manifold 44 is connected to the cylinder block 2;

[0047] The intake end of the air supply pipeline 7 is located between the intercooler 42 and the throttle valve 43;

[0048] The first branch pipeline 92 is connected to the intake end of the compressor 41.

[0049] Among them, the intake end of the air supply pipeline 7 can be arranged downstream of the intercooler 42. Because the temperature of the gas is lower after intercooling and the air flow and temperature uniformity are good, arranging the intake end of the air supply pipeline 7 here is beneficial to the stability of the air supply flow entering the crankcase 3.

[0050] This embodiment further defines the connection positions of the air supply pipeline 7 and the intake unit 4, as well as the connection position of the first branch pipeline 92 and the intake unit 4. Specifically, the intake end of the air supply pipeline 7 is located between the intercooler 42 and the throttle valve 43, and the first branch pipeline 92 is communicated with the intake end of the compressor 41; that is, the intake unit 4 replenishes the fresh air compressed by the compressor 41 and cooled by the intercooler 42 into the crankcase 3, and actively scavenges the mixed oil and gas in the crankcase 3. The scavenged mixed oil and gas can enter the intake end of the compressor 41 in the intake unit 4 via the first branch pipeline 92 after passing through the oil-gas separation unit 6. Thus, the secondary cyclic combustion of the scavenged gas can be realized, and the gas flow in the crankcase 3 can be achieved, effectively improving the ventilation capacity of the crankcase 3, quickly exhausting the leaked hydrogen, and controlling the hydrogen concentration in the crankcase 3 within a reasonable range.

[0051] In some embodiments, the exhaust unit 5 includes an exhaust manifold 51, a turbine 52, and the three-way catalytic converter 53 connected in sequence;

[0052] The exhaust manifold 51 is communicated with the cylinder block 2;

[0053] The exhaust end of the second branch pipeline 93 is located between the turbine 52 and the three-way catalytic converter 53.

[0054] It should be noted that the turbine 52 in this embodiment is connected to the compressor 41 in the foregoing embodiment by a connecting shaft. During use, the turbine 52 is connected to the exhaust manifold 51. After being blown by the exhaust gas and rotating, the rotational torque is transmitted to the compressor 41 by the connecting shaft, and the compressor 41 compresses the fresh air and enters the intercooler 42.

[0055] This embodiment further defines the connection position of the exhaust end of the second branch pipeline 93 in the exhaust unit 5. Specifically, it is located between the turbine 52 and the three-way catalytic converter 53. That is, the exhaust end of the oil-gas separation unit 6 directly inputs the mixture composed of air and hydrogen into the three-way catalytic converter 53 via the second branch pipeline 93, and the energy of the mixture can be fully utilized to carry out an oxidation-reduction reaction at the three-way catalytic converter 53 to heat the three-way catalytic converter 53. Thus, another gas flow mode in the crankcase 3 is realized, effectively improving the ventilation capacity of the crankcase 3.

[0056] In some embodiments, the crankcase ventilation system further includes: a cylinder head 1 and a blow-by pipeline 8. The cylinder head 1 is located at the top of the cylinder block 2. A gas supply port is provided at the lower part of the crankcase 3, and the gas supply port is communicated with the air supply pipeline 7; one end of the blow-by pipeline 8 is communicated with the upper part of the crankcase 3, and the other end is communicated with the oil-gas separation unit 6.

[0057] This embodiment further defines the connection positions of the air supply pipeline 7 and the crankcase 3, as well as the connection positions of the oil-gas separation unit 6 and the crankcase 3. Specifically, an air supply port is provided at the lower part of the crankcase 3, and a blow-by gas pipeline 8 is connected to the upper part of the crankcase 3. That is, the intake port of the blow-by gas pipeline 8 is located at the upper part of the crankcase 3, and its exhaust port is located on the side wall of the cylinder head 1.

[0058] During specific implementation, the fresh air of the intake unit 4 enters the crankcase 3 through the air supply port at the lower part of the crankcase 3, purges the gas in the crankcase 3 from bottom to top, and the swept mixed oil and gas enters the oil-gas separation unit 6 through the blow-by gas pipeline 8 at the upper part of the crankcase 3. This bottom-to-top purging method is beneficial to make the mixing of engine oil and gas, fresh air, and hydrogen in all areas of the crankcase 3 more uniform, so that hydrogen does not accumulate in a certain area of the crankcase 3, avoiding local explosion.

[0059] In some embodiments, the oil-gas separation unit 6 includes a connected first oil-gas separator 61 and the second oil-gas separator 62; the intake end of the first oil-gas separator 61 is communicated with the crankcase, the outlet end of the first oil-gas separator 61 is communicated with the intake end of the second oil-gas separator 62, and the exhaust end of the second oil-gas separator 62 is communicated with the three-way catalytic converter 53 of the intake unit 4 or the exhaust unit 5.

[0060] Among them, at least part of the first oil-gas separator 61 is located in the cylinder head 1, and the second oil-gas separator 62 is located outside the cylinder head 1. The first oil-gas separator 61 is a labyrinth separator, and the second oil-gas separator 62 is a centrifugal separator. Since the labyrinth separator is in a flat long strip shape and is adapted to the internal space of the cylinder head, that is, part or all of the first oil-gas separator 61 can be located in the cylinder head, while the centrifugal separator is spherical and not adapted to the space of the cylinder head 1, so it can be arranged outside the cylinder head 1.

[0061] Among them, both the first oil-gas separator 61 and the second oil-gas separator 62 are provided with oil outlets (not shown in the figure), and the oil outlets are communicated with the crankcase 3.

[0062] Since the mixed oil and gas in the crankcase 3 is diluted by fresh air, while the hydrogen concentration is diluted, the concentration of the oil and gas is also diluted. The decrease in the oil and gas concentration is not conducive to the subsequent oil and gas separation by the oil and gas separation unit 6. Therefore, in this embodiment, two-stage oil and gas separation is selected. The first oil and gas separator 61 is a labyrinth separator, that is, a passive oil and gas separator. The mixed oil and gas entering the first oil and gas separator 61 collides with the labyrinth side wall in the separator, causing the oil and gas to separate. The second oil and gas separator 62 is a centrifugal separator, that is, an active oil and gas separator. The mixed oil and gas entering the second oil and gas separator 62 rotates at a high speed in the separator to achieve centrifugal oil and gas separation. That is, this two-stage oil and gas separation first performs rough separation and then fine separation on the mixed oil and gas to ensure the oil and gas separation effect. In addition, the use of a centrifugal oil and gas separator for the second oil and gas separator 62 will also form a negative pressure in the corresponding pipeline, increasing the flow rate of the mixed oil and gas in the pipeline. In the case of a higher flow rate, the inertia of the oil molecules is higher than that of the air molecules. Therefore, the chance of hitting the labyrinth wall increases, significantly improving the separation efficiency of the mixed oil and gas in the first oil and gas separator.

[0063] In addition, the present application also provides a vehicle including the crankcase ventilation system described in any of the above. The beneficial effects of this vehicle are the same as those of the crankcase ventilation system in the above embodiments and will not be elaborated here.

[0064] Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the present application (including the claims) is limited to these examples; under the concept of the present application, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the embodiments of the present application as described above. For the sake of brevity, they are not provided in detail.

[0065] In addition, for the sake of simplicity of description and discussion, and in order not to make the embodiments of the present application difficult to understand, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. In addition, the device may be shown in block diagram form to avoid making the embodiments of the present application difficult to understand, and this also takes into account the fact that the details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present application will be implemented (that is, these details should be fully within the understanding of those skilled in the art). In the case where specific details (such as circuits) are set forth to describe the exemplary embodiments of the present application, it will be apparent to those skilled in the art that the embodiments of the present application can be implemented without these specific details or with variations of these specific details. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0066] Embodiments of the present application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present application shall be included within the protection scope of the present application.

Claims

1. A crankcase ventilation system, characterized in that: include: A cylinder block and a crankcase connected up and down; An air intake unit and an exhaust unit are respectively connected to the cylinder body, and the exhaust unit includes a three-way catalytic converter; the crankcase is connected to the air intake unit through an air supply line; An oil-gas separation unit, an intake end of which is communicated with the crankcase, and an exhaust end of which is communicated with a three-way catalytic converter of the intake unit or the exhaust unit.

2. The crankcase ventilation system according to claim 1, characterized in that It also includes a tail sweep main pipeline, a first branch pipeline, and a second branch pipeline. The exhaust end of the oil-gas separation unit is connected to the tail sweep main pipeline, the first branch pipeline is connected to the intake unit, and the second branch pipeline is connected to the three-way catalytic converter of the exhaust unit. A tail sweep valve is provided on the tail sweep main pipeline, and the tail sweep valve is used to connect the tail sweep main pipeline with the first branch pipeline or the second branch pipeline.

3. The crankcase ventilation system according to claim 2, characterized in that: The air intake unit comprises a compressor, an intercooler, a throttle valve and an intake manifold connected in sequence; The intake manifold is in communication with the cylinder block; The air inlet end of the air supply line is located between the intercooler and the throttle valve; The first branch pipeline is in communication with an air inlet end of the compressor.

4. The crankcase ventilation system according to claim 2, characterized in that: The exhaust unit includes an exhaust manifold, a turbine and the three-way catalytic converter connected in sequence; The exhaust manifold is in communication with the cylinder block; The exhaust end of the second branch line is located between the turbine and the three-way catalyst.

5. The crankcase ventilation system according to claim 1, characterized in that It also includes a cylinder head and a blowby gas pipeline. The cylinder head is located on the top of the cylinder body. An air supply port is provided at the lower part of the crankcase, and the air supply port is connected to the air supply pipeline. One end of the blowby gas pipeline is connected to the upper part of the crankcase, and the other end is connected to the oil-gas separation unit.

6. The crankcase ventilation system according to claim 1, characterized in that The oil-gas separation unit includes a first oil-gas separator and a second oil-gas separator connected to each other; the intake end of the first oil-gas separator is connected to the crankcase, the outlet end of the first oil-gas separator is connected to the intake end of the second oil-gas separator, and the exhaust end of the second oil-gas separator is connected to the three-way catalytic converter of the intake unit or the exhaust unit.

7. The crankcase ventilation system according to claim 6, characterized in that At least a portion of the first oil-gas separator is located inside the cylinder head, and the second oil-gas separator is located outside the cylinder head.

8. The crankcase ventilation system according to claim 6, characterized in that The first oil-gas separator is a labyrinth separator, and the second oil-gas separator is a centrifugal separator.

9. The crankcase ventilation system according to claim 6, characterized in that The first oil-gas separator and the second oil-gas separator are both provided with an oil outlet, and the oil outlet is communicated with the crankcase.

10. A vehicle, characterized in that: Comprising a crankcase ventilation system as described in any one of claims 1-9.

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