Oil mist separation system and engine

Abstract

The application relates to an oil mist separation system and an engine, wherein the oil mist separation system is applied to the engine, the engine comprises a crankcase, and the oil mist separation system comprises: a gas extraction device, an inlet of the gas extraction device being communicated with a gas outlet of the crankcase; and an oil mist separator, an inlet of the oil mist separator being communicated with an outlet of the gas extraction device. The oil mist separation system can extract crankcase blow-by gas to the oil mist separator, so that the negative pressure environment of the crankcase is more stable.

Description

Technical Field

[0001] This application relates to the field of engine technology, and in particular to an oil mist separation system and an engine. Background Technology

[0002] In an engine, the crankcase primarily houses components such as the crankshaft and connecting rods. During engine operation, the crankcase typically needs to maintain a negative pressure environment to prevent problems such as seal failure and blow-by contamination. In traditional engines, this negative pressure environment is usually achieved through a crankcase ventilation system. However, this system cannot maintain negative pressure under all operating conditions, making it difficult to maintain a stable negative pressure environment in the crankcase. Utility Model Content

[0003] Based on this, this application proposes an oil mist separation system that can extract crankcase blow-by gas to the oil mist separator, thereby making the negative pressure environment of the crankcase more stable.

[0004] On one hand, this application provides an oil mist separation system applied to an engine, the engine including a crankcase, the oil mist separation system including: an air extraction device, the inlet of the air extraction device being connected to the air outlet of the crankcase; and an oil mist separator, the inlet of the oil mist separator being connected to the outlet of the air extraction device.

[0005] Optionally, the oil mist separation system includes a pressure monitoring module configured to monitor the air pressure upstream of the extraction device.

[0006] Optionally, the oil mist separation system also includes a control module, which is configured to receive the pressure monitoring results from the pressure monitoring module and adjust the power of the air extraction device according to the pressure monitoring results so that the crankcase air pressure is less than or equal to a first preset air pressure.

[0007] Optionally, the control module is configured to obtain a real-time pressure difference based on the pressure monitoring result and a first preset air pressure, and adjust the power of the pumping device according to the real-time pressure difference.

[0008] Optionally, the engine also includes a turbocharger; the oil mist separation system also includes: a venturi tube, the diffuser of which is connected to the intake of the turbocharger; and the throat of the venturi tube is connected to the outlet of the oil mist separator.

[0009] Optionally, the oil mist separation system further includes: a first branch flow path, the inlet of which is connected to the outlet of the oil mist separator; the outlet of the first branch flow path is connected to the throat of the venturi tube; and a first one-way valve is provided on the first branch flow path.

[0010] Optionally, the oil mist separation system may also include: a second branch flow path, the inlet of which is connected to the outlet of the oil mist separator; the outlet of the second branch flow path is connected to the throat of the venturi tube, and a first throttling orifice is provided on the second branch flow path.

[0011] Optionally, the first check valve includes an elastic element and a blocking element; wherein the blocking element is configured to block the first diversion passage under the elastic force of the elastic element; wherein when the difference between the air pressure on the inlet side of the first check valve and the air pressure on the outlet side of the first check valve is greater than a preset pressure difference, the blocking element can overcome the elastic force of the elastic element, so that at least part of the first diversion passage is open.

[0012] Optionally, the engine also includes an intake manifold and a combustion chamber; one end of the intake manifold is connected to the outlet of the turbocharger; the other end of the intake manifold is connected to the intake of the combustion chamber.

[0013] On the other hand, this application also provides an engine that includes the aforementioned oil mist separation system.

[0014] The embodiments provided in this application provide a more stable negative pressure environment in the crankcase by installing an air extraction device between the crankcase outlet and the oil mist separator inlet to extract crankcase blow-by air to the oil mist separator. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of an engine provided in one embodiment of this application.

[0016] Explanation of reference numerals in the attached figures

[0017] 1000, Engine; 100, Oil mist separation system; 110, Air extraction device; 111, Pressure monitoring module; 120, Oil mist separator; 130, First branch path; 131, First one-way valve; 1311, Elastic element; 1312, Sealing element; 140, Second branch path; 141, First throttle orifice; 150, Second one-way valve; 160, Venturi tube; 161, Diffuser; 162, Throat; 163, Air pressure supply port; 170, Partial load passage; 171, Third one-way valve; 172, Second throttle orifice; 180, Air replenishment passage; 181, Fourth one-way valve; 182, Third throttle orifice; 190, Oil return pipe; 200, Crankcase; 300, Turbocharger; 400, Intake manifold; 500, Combustion chamber; 600, Intercooler; 700, Air filter. Detailed Implementation

[0018] To make the technical solution and beneficial effects of this application more apparent and understandable, a detailed description is provided below by listing specific embodiments. The accompanying drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which this application pertains.

[0019] Researchers have found that crankcase pressure is easily affected by several factors during engine operation. Firstly, the reciprocating motion of the piston above the crankcase causes changes in the volume of the crankcase cavity, leading to a periodic increase in crankcase pressure. Secondly, during piston movement, exhaust gases from the combustion chamber can seep into the crankcase through piston gaps—a phenomenon known as crankcase blow-by—which also increases crankcase pressure. However, in traditional crankcase ventilation systems, blow-by can be extracted by manifold negative pressure or post-turbocharger negative pressure under certain operating conditions. But under certain conditions, where there is no negative pressure at the turbocharger or manifold ends, the airflow within the crankcase sometimes cannot be effectively expelled, making it difficult to maintain a stable negative pressure environment in the crankcase.

[0020] Based on this, researchers proposed an oil mist separation system. By setting an air extraction device between the crankcase outlet and the oil mist separator inlet, the blow-by air from the crankcase is extracted to the oil mist separator, thereby making the negative pressure environment of the crankcase more stable.

[0021] refer to Figure 1 This application provides an oil mist separation system 100, applied to an engine 1000, which includes a crankcase 200. The oil mist separation system 100 includes an extraction device 110 and an oil mist separator 120. The inlet of the extraction device 110 is connected to the outlet of the crankcase 200. The inlet of the oil mist separator 120 is connected to the outlet of the extraction device 110.

[0022] It should be noted that, Figure 1 This is a structural schematic diagram of the engine 1000, used to illustrate the internal structure of the oil mist separation system 100 in this embodiment, as well as the connection relationship between the oil mist separation system 100 and other components of the engine 1000.

[0023] It is understood that the exhaust device 110 refers to various devices with active exhaust function, such as fans, vacuum pumps, etc., and there is no specific limitation here. In this embodiment, the inlet of the exhaust device 110 is connected to the outlet of the crankcase 200, directly extracting the blow-by gas from the crankcase 200, and then transmitting the blow-by gas from the crankcase 200 to the inlet of the oil mist separator 120; the oil mist separator 120 receives the blow-by gas from the crankcase 200 from the inlet, performs oil mist separation on the blow-by gas from the crankcase 200, obtains clean gas and oily substances, and then outputs clean gas from the outlet.

[0024] In the above embodiments, by providing an air extraction device 110 between the air outlet of the crankcase 200 and the inlet of the oil mist separator 120, the blown air from the crankcase 200 is extracted to the oil mist separator 120, thereby making the negative pressure environment of the crankcase 200 more stable.

[0025] Typically, there is a negative pressure environment downstream of the oil mist separator 120 to allow the oil mist separator 120 to separate the oil in the blow-by gas, thereby reducing the air pressure inside the oil mist separator 120. This prevents the air extraction load of the air extraction device 110 from being too high and reduces power consumption.

[0026] Furthermore, in related technologies, the crankcase pressure is regulated by a crankcase ventilation system located downstream of the oil mist separator in an oil mist separation system. This requires the crankcase ventilation system to indirectly regulate the crankcase pressure through the oil mist separator. Such indirect regulation often suffers from slow regulation speed and low regulation accuracy. In this embodiment, however, the air extraction device 110 is connected to the air outlet of the crankcase 200, allowing for crankcase pressure regulation without going through the oil mist separator 120. Therefore, problems such as delayed regulation speed and low regulation accuracy can be avoided.

[0027] Furthermore, in this embodiment, the air extraction device 110 can adjust its power according to different operating conditions of the crankcase 200 to actively regulate the air pressure of the crankcase 200, thus providing good flexibility and applicability.

[0028] refer to Figure 1 In this embodiment, the oil mist separation system 100 includes a pressure monitoring module 111, which is configured to monitor the air pressure upstream of the air extraction device 110.

[0029] It is understood that the upstream of the extraction device 110 refers to the connecting pipe between the extraction device 110 and the crankcase 200, as well as the inside of the crankcase. The pressure monitoring module 111 can be installed in multiple locations, such as inside the crankcase 200, at the crankcase 200's outlet, or at the extraction device 110's inlet. The air pressure upstream of the extraction device 110 is close to the air pressure inside the crankcase 200; therefore, the pressure monitoring module 111 can monitor the air pressure inside the crankcase 200 by monitoring the air pressure upstream of the extraction device 110, thus providing data support for various control methods. These control methods can be diverse, such as extraction power control of the extraction device 110 and safety status alarms for the engine 1000. Furthermore, when the pressure monitoring module 111 is located outside the crankcase 200, it facilitates maintenance and disassembly.

[0030] The pressure monitoring module 111 can be a pressure sensor or a pressure gauge.

[0031] In this embodiment, the vacuum extraction device 110 also includes a control module (not shown). The control module is configured to receive the pressure monitoring results from the pressure monitoring module 111 and adjust the power of the vacuum extraction device 110 according to the pressure monitoring results, ensuring that the crankcase 200 pressure is less than or equal to a first preset pressure. The control module can perform closed-loop control of the crankcase 200 pressure based on the pressure monitoring results, ensuring that the crankcase 200 always maintains a negative pressure environment, preventing engine 1000 malfunction due to excessively high crankcase 200 pressure, thereby improving the reliability of the engine 1000. The first preset pressure refers to a preset pressure value that ensures the crankcase 200 maintains a negative pressure environment throughout the entire process. The closed-loop control method of the control module can be various, such as proportional control, integral control, and proportional-integral control.

[0032] Optionally, the control module is also configured to obtain a real-time pressure difference based on the pressure monitoring result and a first preset air pressure, and adjust the power of the vacuum device 110 according to the real-time pressure difference. Furthermore, the power change of the vacuum device 110 is linearly related to the real-time pressure difference. The control module can improve response speed and simplify control logic to further optimize the crankcase air pressure regulation function of the vacuum device 110.

[0033] It is understandable that the closed-loop control method of the control module is proportional control, because its input parameter is the real-time differential pressure, its output parameter is the power change of the pumping device 110, and the output parameter is linearly related to the input parameter.

[0034] Because proportional control has the advantages of fast response speed and simple control logic, and is more suitable for scenarios where the adjustment accuracy requirement of crankcase 200 pressure is not high, the control module can further optimize the crankcase air pressure adjustment function of the air extraction device 110.

[0035] refer to Figure 1 In this embodiment, the engine 100 also includes a turbocharger 300; the oil mist separation system 100 also includes a venturi tube 160, the diffuser tube 161 of the venturi tube 160 being connected to the air inlet of the turbocharger 300; and the throat tube 162 of the venturi tube 160 being connected to the outlet of the oil mist separator 120.

[0036] Understandably, in engine 1000, the turbocharger 300 is primarily used to increase airflow pressure, such as... Figure 1 As shown, the intake port of the turbocharger 300 is connected to the external air environment through the air filter 700, and the exhaust port of the turbocharger 300 is connected to the combustion chamber 500 through the intercooler 600 and the intake manifold 400. The specific functions of the air filter 700, the intake manifold 400, and the intercooler 600 will not be elaborated here. When the turbocharger 300 is running, it draws airflow from the intake port for compression, thereby creating a negative pressure environment at the intake port of the turbocharger 300.

[0037] Additionally, it's understandable that Venturi tube 160 refers to a specific pipe structure with two tapered sections. Specifically, refer to... Figure 1 The venturi tube 160 includes a diffuser 161 and a throat 162. The throat 162 includes a converging section and a narrowing section. Both the converging sections of the diffuser 161 and the throat 162 are tapered pipe structures, while the narrowing section of the throat 162 is a cylindrical pipe structure. The wide end of the diffuser 161 connects to the air inlet of the booster 300, the narrow end of the diffuser 161 connects to one end of the narrowing section of the throat 162, the other end of the narrowing section connects to the narrow end of the converging section, and the wide end of the converging section connects to the outlet of the oil mist separator 120. The wide end refers to the port with the larger cross-sectional area on either side of the tapered pipe structure, and the narrow end refers to the port on the other side. Furthermore, the rate of change of the converging section of the throat 162 is greater than that of the diffuser 161, where the rate of change of the pipe's cross-sectional area refers to the rate at which the cross-sectional area of ​​the tapered pipe changes with the length of the pipe. The function of the Venturi tube 160 is to increase the gas velocity at the narrow section of the throat 162 when the gas flows from the throat 162 to the diffuser 161, thus creating a stable negative pressure. This stable negative pressure can increase the gas flow rate and enhance the stability of the gas flow, preventing fluctuations in gas velocity due to pressure difference changes.

[0038] In this embodiment, the diffuser 161 of the venturi tube 160 is connected to the air inlet of the booster 300, and the throat 162 is connected to the outlet of the oil mist separator 120. When the booster 300 is running, the negative pressure environment at the booster 300's air inlet can draw gas from the oil mist separator 120, causing the gas to flow into the booster 300's air inlet through the venturi tube 160, thereby reducing the gas pressure within the oil mist separator 120. This helps reduce the suction load on the suction device 110, thereby reducing the power consumption of the suction device 110 and achieving energy-saving effects.

[0039] Meanwhile, the Venturi tube 160 can use its specific pipe structure to form a stable negative pressure at the narrow section of the throat 162. This stable negative pressure can enhance the negative pressure suction effect on the gas in the oil mist separator 120, improve the gas flow rate and stability, and thus optimize the energy-saving effect of the oil mist separation system 100.

[0040] refer to Figure 1 In this embodiment, the oil mist separation system 100 further includes a first branch flow path 130. The inlet of the first branch flow path 130 is connected to the outlet of the oil mist separator 120, and the outlet of the first branch flow path 130 is connected to the throat 162 of the venturi tube 160. A first one-way valve 131 is provided on the first branch flow path 130.

[0041] In the aforementioned oil mist separation system 100, a first one-way valve 131 is provided in the first diversion path 130, which enables one-way gas flow, allowing gas to flow only from the inlet to the outlet of the first diversion path 130. This ensures that the first diversion path 130 can guarantee that the gas from the inlet of the turbocharger 300 will not flow back into the oil mist separator 120 through the venturi tube 160, causing an abnormal increase in the crankcase 200 pressure, thereby improving the reliability of the oil mist separation system 100.

[0042] Further reference Figure 1 In this embodiment, the oil mist separation system 100 further includes a second branch flow path 140, the inlet of which is connected to the outlet of the oil mist separator 120. The outlet of the second branch flow path 140 is connected to the throat 162 of the venturi tube 160. A first throttling orifice 141 is provided on the second branch flow path 140.

[0043] It is understandable that the first throttling orifice 141 refers to a small channel with a flow-limiting function. The second branch flow path 140 is provided with the first throttling orifice 141, which makes the gas flow rate of the second branch flow path 140 less than the gas flow rate of the first branch flow path 130 when the first one-way valve 131 is open.

[0044] In the oil mist separation system 100 described above, the first branch flow path 130 and the second branch flow path 140 are arranged in parallel. The first branch flow path 130 is also provided with a first one-way valve 131, and the second branch flow path 140 is provided with a first throttling orifice 141. This enables dynamic adjustment of the gas flow between the oil mist separator 120 and the venturi tube 160 to optimize the energy-saving effect.

[0045] Specifically, the first one-way valve 131 has an opening pressure. When the outlet pressure of the oil mist separator 120 is greater than the pressure at the throat 162 of the venturi tube 160, but the pressure difference is insufficient to overcome the opening pressure of the first one-way valve 131, the first one-way valve 131 closes. The gas in the oil mist separator 120 can only flow to the booster 300 through the second branch path 140, and the gas flow rate is relatively small at this time. When the outlet pressure of the oil mist separator 120 continues to increase, and the pressure difference is sufficient to overcome the opening pressure of the first one-way valve 131, the first one-way valve 131 opens. The gas in the oil mist separator 120 flows to the booster 300 simultaneously through the first branch path 130 and the second branch path 140, and the gas flow rate is relatively large at this time, thus enabling rapid venting of the gas in the oil mist separator 120. This achieves dynamic regulation of the gas flow rate.

[0046] In addition, the second branch flow path 140 is provided with a first throttling orifice 141. The first throttling orifice 141 can limit the flow rate of the second branch flow path 140, and at the same time generate a pressure drop on both sides of the second branch flow path 140 to reduce gas flow fluctuations, thereby making the gas flow between the oil mist separator 120 and the booster 300 more stable.

[0047] refer to Figure 1 In this embodiment, the first one-way valve 131 includes an elastic element 1311 and a sealing element 1312; wherein, the sealing element 1312 is configured to block the first diversion passage 130 under the elastic force of the elastic element 1311. When the difference between the inlet pressure and the outlet pressure of the first one-way valve 131 is greater than a preset pressure difference, the sealing element 1312 can overcome the elastic force of the elastic element 1311, allowing at least a portion of the first diversion passage 130 to be open. Through the cooperation of the sealing element 1312 and the elastic element 1311, the first one-way valve 131 can adjust its opening degree according to the pressure difference on both sides, making the dynamic adjustment of the gas flow rate of the first diversion passage 130 more precise. The preset pressure difference corresponds to the opening pressure of the first one-way valve 131.

[0048] Furthermore, in related technologies, dynamic regulation of gas flow rate is typically achieved using complex structures such as throttle valves or diaphragm valves. However, this embodiment uses a first one-way valve 131 and a second diversion path 140 in conjunction to replace the throttle valve or diaphragm valve. The one-way valve is a simple one-way valve with an elastic element 1311 and a sealing element 1312, which is relatively inexpensive, and the second diversion path 140 is a simple pipe structure. Therefore, the oil mist separation system 100 of this embodiment has the advantages of simple structure and low cost.

[0049] refer to Figure 1 In this embodiment, the engine 1000 also includes an intake manifold 400 and a combustion chamber 500; one end of the intake manifold 400 is connected to the outlet of the turbocharger 300; the other end of the intake manifold 400 is connected to the intake of the combustion chamber 500.

[0050] Understandably, in engine 1000, combustion chamber 500 is located above crankcase 200, separated by a piston (not shown). When engine 1000 is operating, the piston reciprocates, causing periodic changes in the air pressure in crankcase 200, combustion chamber 500, and intake manifold 400 connected to combustion chamber 500. When the piston depresses, the air pressure in intake manifold 400 decreases, creating a negative pressure environment.

[0051] In this embodiment, reference Figure 1The throat 162 also has a pressure supply port 163, which connects to the intake manifold 400. This allows the intake manifold 400 to connect to the outlet of the oil mist separator 120, thereby enabling the negative pressure environment of the intake manifold 400 to attract gas from the oil mist separator 120. Specifically, when the air pressure in the intake manifold 400 is lower than the outlet air pressure of the oil mist separator 120, gas can enter the intake manifold 400 from the oil mist separator 120 sequentially through two branch paths (130, 140) and the throat 162 of the venturi tube 160. This reduces the air pressure within the oil mist separator 120, further reducing the power consumption of the extraction device 110 and improving energy efficiency.

[0052] refer to Figure 1 In this embodiment, the oil mist separation system 100 further includes a second one-way valve 150. The inlet of the second one-way valve 150 is connected to the outlet of the oil mist separator 120; the outlet of the second one-way valve 150 is connected to the inlet of the first branch flow path 130 and the inlet of the second branch flow path 140. The second one-way valve 150 is used to ensure that when the first one-way valve 131 of the first branch flow path 130 is closed, the air inlet gas of the turbocharger 300 will not flow back into the oil mist separator 120 through the second branch flow path 140, causing an abnormal increase in the crankcase 200 pressure, thereby further improving the reliability of the oil mist separation system 100.

[0053] Optionally, the oil mist separation system 100 may further include a partial load passage 170 disposed between the outlet of the oil mist separator 120 and the intake manifold 400, to further utilize the periodic negative pressure environment of the intake manifold 400 to reduce the power consumption of the extraction device 110. Specifically, in this embodiment, refer to... Figure 1 The partial load channel 170 is equipped with a third one-way valve 171 and a second throttling orifice 172. The inlet of the third one-way valve 171 is connected to the outlet of the oil mist separator 120; the outlet of the third one-way valve 171 is connected to the inlet of the second throttling orifice 172, and the outlet of the second throttling orifice 172 is connected to the intake manifold 400. The third one-way valve 171 provides one-way communication, preventing gas from the intake manifold 400 from flowing back into the oil mist separator 120. The second throttling orifice 172 restricts flow, preventing excessive gas from entering the intake manifold 400 and interfering with its normal operation.

[0054] It is understood that the structural configuration of the partial load channel 170 in this embodiment is exemplary, and the partial load channel 170 can also be constructed by other structures. For example, a PCV valve (Positive Crankcase Ventilation) can be used to construct the partial load channel 170 to achieve the above function. The specific principle will not be elaborated here.

[0055] Optionally, the oil mist separation system 100 may further include a gas supply channel 180, which can supply external gas to the crankcase 200 to prevent the crankcase 200 from having excessively low pressure. Specifically, in this embodiment, refer to... Figure 1 An air supply channel 180 is located between the air inlet of the turbocharger 300 and the air inlet of the crankcase 200, and is equipped with a fourth one-way valve 181 and a third throttle orifice 182. The inlet of the third throttle orifice 182 is connected to the external air environment through an air filter 700, and the outlet of the third throttle orifice 182 is connected to the inlet of the fourth one-way valve 181. The outlet of the fourth one-way valve 181 is connected to the air inlet of the crankcase 200. The fourth one-way valve 181 has an opening pressure; when the air pressure in the crankcase 200 is lower than a second preset air pressure, the fourth one-way valve 181 opens, allowing external air to enter the crankcase 200, thus supplying air. The second preset air pressure is lower than the first preset air pressure. Furthermore, the third throttle orifice 182 also has a flow-limiting function to prevent excessive air from entering the crankcase 200 and causing an excessive rise in the crankcase 200 air pressure.

[0056] refer to Figure 1 In this embodiment, the oil mist separation system 100 further includes an oil return pipe 190. The inlet of the oil return pipe 190 is connected to the oil mist separator 120, and the outlet of the oil return pipe 190 is connected to the crankcase 200. The oil return pipe 190 is used to recover the oily substances separated by the oil mist separator 120 to the crankcase 200.

[0057] refer to Figure 1 Another embodiment of this application also provides an engine 1000, which includes the aforementioned oil mist separation system 100. The engine 1000, by providing an air extraction device 110 between the outlet of the crankcase 200 and the inlet of the oil mist separator 120, draws out blow-by air from the crankcase 200 to the oil mist separator 120, thereby making the negative pressure environment of the crankcase 200 more stable and thus providing higher reliability.

[0058] In this application, the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the purpose of simplifying the description of this application and do not indicate that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. In other words, they should not be construed as limitations on this application.

[0059] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating the relative importance of the indicated features or the number of indicated technical features. Therefore, a feature specified as "first" or "second" may explicitly include at least one of those features. In this application, "multiple" means at least two, such as two, three, etc.; "several" means at least one, such as one, two, three, etc., unless otherwise explicitly specified.

[0060] In this application, unless otherwise expressly defined, the terms "installation," "connection," "linking," "fixing," "setting," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can also refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0061] In this application, unless otherwise expressly defined, the terms "above," "on top of," "over," "above," "below," "below," "below," or "below" for "first feature over second feature" can refer to the first and second features being in direct contact, or to the first and second features being in indirect contact through an intermediate medium. Furthermore, "above," "over," and "below" for "first feature over second feature" can mean the first feature is directly above or diagonally above the second feature, or simply indicates that the horizontal height of the first feature is higher than the horizontal height of the second feature. Similarly, "below," "below," and "below" for "first feature over second feature" can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the horizontal height of the first feature is lower than the horizontal height of the second feature.

[0062] It should be understood that the above embodiments are exemplary and are not intended to encompass all possible implementations included in the claims. Various modifications and changes can be made to the above embodiments without departing from the scope of this disclosure. Similarly, the various technical features of the above embodiments can be arbitrarily combined to form other embodiments of this application that may not be explicitly described. Therefore, the above embodiments only illustrate several implementations of this application and do not limit the scope of protection of this patent application.

Claims

1. An oil mist separation system applied to an engine, said engine including a crankcase, characterized in that, The oil mist separation system includes: An air extraction device, wherein the inlet of the air extraction device is connected to the air outlet of the crankcase; An oil mist separator, wherein the inlet of the oil mist separator is connected to the outlet of the air extraction device; A pressure monitoring module, configured to monitor the air pressure upstream of the air extraction device; The control module is configured to receive the pressure monitoring results from the pressure monitoring module and adjust the power of the air extraction device according to the pressure monitoring results so that the air pressure in the crankcase is less than or equal to a first preset air pressure.

2. The oil mist separation system according to claim 1, characterized in that, The control module is configured to obtain a real-time pressure difference based on the pressure monitoring result and the first preset air pressure, and to adjust the power of the pumping device based on the real-time pressure difference.

3. The oil mist separation system according to claim 2, characterized in that, The engine also includes a turbocharger; the oil mist separation system also includes: The venturi tube has a diffuser tube connected to the air inlet of the turbocharger; the throat of the venturi tube is connected to the outlet of the oil mist separator.

4. The oil mist separation system according to claim 3, characterized in that, The oil mist separation system also includes: The first branch flow path has its inlet connected to the outlet of the oil mist separator; its outlet is connected to the throat of the venturi tube; and a first one-way valve is provided on the first branch flow path.

5. The oil mist separation system according to claim 4, characterized in that, The oil mist separation system further includes: a second branch flow path, the inlet of which is connected to the outlet of the oil mist separator; the outlet of the second branch flow path is connected to the throat of the venturi tube; and a first throttling orifice is provided on the second branch flow path.

6. The oil mist separation system according to claim 4, characterized in that, The first one-way valve includes a resilient element and a blocking element; wherein, the blocking element is configured to block the first diversion path under the elastic force of the resilient element; wherein, When the pressure difference between the inlet side of the first one-way valve and the outlet side of the first one-way valve is greater than a preset pressure difference, the sealing element can overcome the elastic force of the elastic element, so that at least part of the first diversion path is open.

7. The oil mist separation system according to claim 6, characterized in that, The engine also includes an intake manifold and a combustion chamber; one end of the intake manifold is connected to the outlet of the turbocharger; the other end of the intake manifold is connected to the intake of the combustion chamber.

8. An engine, characterized in that, The engine includes the oil mist separation system according to any one of claims 1 to 7.

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