Crankcase ventilation system for an internal combustion engine

Abstract

The invention provides a crankcase ventilation system (100) for a internal combustion engine (1000), for instance a hydrogen internal combustion engine, the crankcase ventilation system (100) comprising an intake tract (110) for supplying air to the crankcase ventilation system (100), an exhaust gas turbocharger (120) connected to the intake tract (110), the input being adapted to be connected to an exhaust (1004) of the internal combustion engine (1000), the exhaust gas turbocharger (120) being adapted to stream the supplied air into a feed line (140, 150) of the internal combustion engine (1000), at least one ventilation line (160) adapted to connect the exhaust gas turbocharger (120) to the internal combustion engine (1000), and an electrically controlled disc separator (130) adapted to connect the internal combustion engine (1000) to the intake tract (110) and to the exhaust gas turbocharger (120).

Description

[0001] Description

[0002] Title: Crankcase ventilation system for an internal combustion engine

[0003] Technical Field

[0004] This disclosure relates to crankcase ventilation systems for internal combustion engines, in a motor vehicle. In particular, the present disclosure pertains to a crankcase ventilation system and method for a hydrogen internal combustion engine.

[0005] Background Art

[0006] Crankcase ventilation systems for internal combustion engines are known in background art.

[0007] For instance, international patent application WO 2022 / 258875A1 discusses a ventilation arrangement for a crankcase of a turbocharged dual-fuel or multi-fuel piston engine to evacuate unwanted gases from the crankcase, with the purpose to keep the pressure in the crankcase within acceptable limits.

[0008] In addition, US patent application No. 2016 / 0010614 A1 discusses methods and systems for heating a crankcase in a general engine system. Specifically, Fig. 1 of this documents depicts crankcase heating in a known boosted engine system according to the background art. Specifically, a crankcase 430 is heated by hot, boosted intake air drawn from the downstream of a compressor 502 and directly streamed into the crankcase. A smaller portion of the intake air enters a first passage 606 via an opening 625 and is metered by an aspirator 608. It then flows into a conduit 436 and then into the crankcase 430 via a first oil separator 652. The hot intake air heats the crankcase and the engine internals, thereby expediting engine warm-up. Crankcase vapors are then released and directed past a second oil separator 632 into conduit 622, and then delivered to the engine intake via a passage 614 and an interstitial space 416 in a double wall exhaust manifold 440. This enables a bidirectional air flow between the intake manifold and crankcase, and the oil separators 652, 632 ensure oil separation from crankcase vapors, thereby improving the ventilation. The other numerical references are not described further.

[0009] US patent application No. 2008 / 110443 A1 discloses a blow-by gas processing apparatus applicable to an internal combustion engine. German patent application No. DE 10 2019 101141 A1 discloses a ventilation device for a crankcase of an internal combustion engine with a centrifugal oil separator which can be driven by an electric machine via a shaft.

[0010] German patent application No. DE 10 2016 217440 A1 discloses a separating device for separating solid and liquid contaminants from a gas flow.

[0011] German patent application No. DE 10 2017 200846 A 1 discloses a conveying device for driving a gas.

[0012] However, the known devices and methods have several disadvantages which need to be remedied for upcoming applications. One of these disadvantages is the drawback that the known crankcase ventilation systems are suitable for internal combustion engines but not for hydrogen powered engines. A disadvantage is that, during the operation of hydrogen combustion engines, gases such as hydrogen and water vapor obtained as a combustion product can be released and (re-)enter the engine crankcase as part of blow-by gases.

[0013] Hydrogen blow-by itself then leads to various issues including decreased combustion efficiency, potential safety hazards due to hydrogen's flammability, increased emissions of unburned hydrocarbons, and the contamination, corrosion, and lubrication breakdown caused by the presence of water vapor in the crankcase as a byproduct of hydrogen combustion.

[0014] Summary of the Invention

[0015] The object of the present disclosure, or invention, is to provide a crankcase ventilation system for combustion engines that addresses the aforementioned disadvantages and improves upon known crankcase ventilation methods and apparatus.

[0016] The invention provides several improvements for combustion engines and is applicable to hydrogen combustion engines and to gas engines, in which high water contents also arise during combustion.

[0017] In an aspect, an active crankcase ventilation system is provided as set forth in the appended claims.

[0018] Specifically, it is provided a crankcase ventilation system for an internal combustion engine, the crankcase ventilation system comprising:

[0019] - an intake tract for supplying air to the crankcase ventilation system,

[0020] - an exhaust gas turbocharger having an input connected to the intake tract, the input being adapted to be connected to an exhaust of the internal combustion engine, the exhaust gas turbocharger being adapted to stream the supplied air into a feed line of the internal combustion engine,

[0021] - at least one ventilation line adapted to connect an output of the exhaust gas turbocharger to an inlet of the internal combustion engine, and

[0022] - an electrically controlled disc separator adapted to connect the exhaust of the internal combustion engine to the intake tract and to the input of the exhaust gas turbocharger, wherein the supplied air which is streamed by the exhaust gas turbocharger into the feed line of the internal combustion engine is hot charge air.

[0023] Herein and / or in an embodiment, the feed line of the internal combustion engine functions as a charge air cooler of the internal combustion engine and comprises an intercooler and / or a throttle valve, preferably both. Herein, a crankcase ventilation system for an internal combustion engine means a crankcase ventilation system adapted to equip an internal combustion engine and / or a crankcase ventilation system adapted to be connected to an internal combustion engine. Herein, one refers equivalently to a gas turbocharger and an exhaust gas turbocharger.

[0024] In operation, a crankcase ventilation system comprising an electrically controlled disc separator rather than a hydraulic disk separator enables the creation of a vacuum in the system when the latter is connected to the internal combustion engine.

[0025] In an embodiment, the internal combustion engine is a hydrogen internal combustion engine.

[0026] In an embodiment, the intake tract comprises an air filter, the air filter being selected among a hydrophobic filter, a photocatalytic filter, and a nano-fiber filter.

[0027] This enables an improvement of the crankcase ventilation system 's overall performance. Specifically, using a hydrophobic filter, a photocatalytic filter or a nano-fiber filter leads to significantly improve the filtration efficiency of the system and to minimize the impact of contaminants on the engine. For instance, nano-fiber technology in air filters can dramatically increase filtration efficiency and reduce pressure drop, as small particles such as hydrogen and water molecules can be captured, making them highly effective in reducing these contents in the blow-by. Photocatalytic Filters usually rely on photocatalysts such as titanium dioxide to break down organic pollutants, including hydrogen and certain volatile compounds. They effectively reduce hydrogen and water content in the blow-by. Hydrophobic filters repel water and are beneficial in preventing moisture from entering the crankcase ventilation system. By reducing water content, they indirectly help in lowering hydrogen content in the blow-by.

[0028] In an embodiment, the at least one ventilation line consists of a single line, called first aeration line, the first aeration line having a diameter selected among 4 millimetres, 5 millimetres, 6 millimetres, 7 millimetres and 8 millimetres.

[0029] Herein and / or in an embodiment, an aeration line is defined as a conduit, a hose, a pipe, or a tubing not comprising any throttle or any restrictor.

[0030] In such a case, the absence of a throttle in the aeration line of the at least one ventilation line allows for an unrestricted air flow when in operation, resulting in effective reduction of hydrogen and water content in the blow-by. Similarly, the absence of a restrictor enables unobstructed airflow, leading to efficient removal of hydrogen and water content in the blow-by.

[0031] In another embodiment, the at least one ventilation line comprises a plurality of lines, called aeration lines, each of the aeration lines having a diameter selected among 4 millimetres, 5 millimetres, 6 millimetres, 7 millimetres and 8 millimetres. The use of several aeration lines connected by one or more access points of the crankcase ventilation system can be advantageous for homogenizing the blow-by and, in particular, a mixture of fresh air.

[0032] In an embodiment the first and / or the at least one ventilation line comprises a throttle and / or a restrictor.

[0033] Advantageously, adding a throttle in the aeration line(s) enables a more accurate regulation of the air flow when in operation, resulting in better control of the hydrogen and water content in the blow-by.

[0034] In an embodiment the electrically controlled disc separator comprises a flow control element.

[0035] This allows for a more precise control of the flow of exhaust gases, while also enabling efficient separation of gases and facilitating optimal regulation of the ventilation process. As a result, it is possible to effectively remove hydrogen and water content in the blow-by, thereby enhancing the overall performance and emissions reduction of the internal combustion engine.

[0036] In an embodiment, the electrically controlled disc separator and the flow control element are configured to ventilate additional air through the at least one ventilation line with a flow value which is larger than 160 litres per minute and lower than 180 litre per minute, and which is preferably equal to 170 litres per minute.

[0037] Herein, flow values such as 160, 170 and 180 litres per minute refer to flow values of additional air in the crankcase ventilation system operating under full load, which can be expressed equivalently under values of degree of scavenging. Herein, scavenging is the process of replacing the exhaust gas in a cycle of the engine with fresh air (or a fuel mixture) for the next cycle.

[0038] Such flow values enable dilution ratios of the blow-by gases of at least 1 :1 at constant negative crankcase pressures.

[0039] In other words, in an embodiment, the electrically controlled disc separator and the flow control element are configured to ventilate additional air through the at least one ventilation line with a dilution ratio of the blow-by gases of at least 1 : 1 at constant negative crankcase pressures.

[0040] In an embodiment the electrically controlled disc separator further comprises a speed monitor and / or a pressure control valve.

[0041] Herein, the speed monitor is also called a separator speed monitor.

[0042] This enables the electrically controlled disc separator, along with the speed monitor, to enforce precise control and efficient separation of exhaust gases, leading to a more effective removal of hydrogen and water content in the blow-by.

[0043] As mentioned, the supplied air which is streamed by the exhaust gas turbocharger into the feed line of the internal combustion engine is hot charge air.

[0044] This enables diluting the blow-by gas with warm and dry air, which in turn leads to a lowering of the hydrogen content below the ignition limit. In parallel, the condensation of water inside the crankcase can be limited significantly, as well as the water content in oils used for the internal combustion engine.

[0045] Advantageously, and when in operation, this leads the hydrogen content in the blow-by to be reduced significantly below the lower ignition limit of 4% when the additional volume flow is of maximum 170 litres per minute. Therefore, the increased volume flow of the ventilation line effectively lowers the hydrogen content in the blow-by, resulting in improved combustion efficiency and reduced emissions.

[0046] More generally, aeration with hot charge air is more effective than the known ventilation systems aiming at lowering the hydrogen content using aeration with cold charge air, i.e. , air with a lower temperature. Aeration with hot charge air also provides better reduction of hydrogen content in the blow-by, leading to enhanced engine performance and reduced emissions compared to aeration with cold charge air.

[0047] In another aspect, an internal combustion engine, comprising a crankcase ventilation system, is provided as set forth in the appended claims.

[0048] Specifically, it is provided a gas internal combustion engine or a hydrogen internal combustion engine, comprising the crankcase ventilation system according to any of the preceding embodiments.

[0049] In another aspect, a method for operating a crankcase ventilation system is provided as set forth in the appended claims.

[0050] Specifically, it is provided a method for operating the crankcase ventilation system according to any of the preceding embodiments, comprising: a) connecting the output of the exhaust gas turbocharger to the feed line of the internal combustion engine, connecting the output of the exhaust gas turbocharger to the inlet of the internal combustion engine using the at least one ventilation line and also connecting the input of the exhaust gas turbocharger to the exhaust of the internal combustion engine using the electrically controlled disc separator, b) supplying air to the crankcase ventilation system using the intake tract, c) streaming the supplied air into the feed line of the internal combustion engine using the gas turbocharger, and d) generating a vacuum within the crankcase ventilation system by operating the electrically controlled disc separator.

[0051] In an embodiment, the method further comprises, after the step c) of streaming and before the step d) of generating the vacuum a step of c2) ventilating hot charge air through the at least one ventilation line at a maximum flow rate larger than 160 litres per minute and lower than 180 litres per minute, and preferably equal to 170 litres per minute, using the crankcase ventilation system connected to the internal combustion engine.

[0052] This enables an enhancement of the ventilation efficiency and an improvement of the removal of hydrogen and water content in the blow-by.

[0053] In other words, in an embodiment, the method further comprises, after the step c) of streaming and before the step d) of generating the vacuum a step of c2) ventilating hot charge air through the at least one ventilation line with a dilution ratio of the blow-by gases of at least 1 :1 at constant negative crankcase pressures.

[0054] Once the step a) of connecting has been implemented, the operation of the crankcase ventilation system can be maintained by repeating the steps b), c), optionally c2) and then d) of supplying, streaming, optionally ventilating, and generating the vacuum successively.

[0055] Brief Description of the Drawings

[0056] In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

[0057] FIG. 1 illustrates a crankcase heating system according to the prior art.

[0058] FIG. 2 shows a crankcase ventilation system connected to an internal combustion engine, such as a hydrogen internal combustion engine, according to an embodiment.

[0059] FIG. 3 shows the steps of a method for operating a crankcase ventilation system connected to a hydrogen internal combustion engine and according to an embodiment.

[0060] Unless otherwise indicated, elements common to or similar to several figures bear the same reference signs and have identical or similar features, so that these common elements are generally not described again for the sake of simplicity.

[0061] Detailed Description of Embodiments The solutions provided in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0062] As shown in Figure 1 , which depicts a crankcase heating system according to the prior art, the crankcase can be heated using boosted intake air drawn from downstream of the compressor and directly channeled into the crankcase.

[0063] As depicted, the majority of the intake air flows past a compressor 502, through a charge air cooler 504, and across an intake throttle 406 into an intake manifold 408. A smaller portion of the boosted intake air is drawn from downstream of the compressor to provide heat to the crankcase 430. This smaller portion of intake air then enters a first passage 606 through an opening 625 located downstream of the compressor 502 and upstream of the charge air cooler 504. Due to compression heating, this portion of intake air is at a boosted pressure and a higher temperature (indicated by diagonal hatch), exceeding the ambient temperature.

[0064] An aspirator 608 is employed to ensure precise regulation of the intake air flow upon entering the first passage 606 from the pressurized source. This aspirator 608 facilitates metered air flow. Fluidically connecting the first passage 606 to conduit 436 establishes a linkage between the crankcase 430 and the intake manifold 408 via the PCV valve 434, which is positioned downstream of the intake throttle 406.

[0065] Upon entering the first passage 606, the intake air is further metered through the aspirator 608 and proceeds across a check valve 610 into the conduit 436. The intake air enters the conduit 436 at junction 642 and flows towards the crankcase 430 through a first oil separator 652. As the hot intake air passes through the first oil separator 652 and enters the crankcase 430, it effectively transfers heat to the crankcase and engine internals, thereby expediting engine warm-up. The crankcase vapors released as a result of drawing in the hot intake air are then directed towards a second oil separator 632 through conduit 622. From there, the crankcase vapors are delivered to the intake passage 418 at a location upstream of the compressor via the passage 614. These crankcase vapors are directed to the compressor inlet, passing through the interstitial space 416 in the double-wall exhaust manifold 440.

[0066] Figure 2 illustrates an active crankcase ventilation system 100 connected to an internal combustion engine 1000 according to an embodiment of the invention and aiming at improving the systems of the prior art, such as the system shown in the previous figure. The crankcase ventilation system 100 comprises an intake tract 110 serving as the air supply source for the system 100 and for the engine 1000 when equipped by the latter. This ensures a continuous flow of fresh air to optimize the performance of the engine.

[0067] An exhaust gas turbocharger 120, located downstream of the intake tract 110 and comprising an input 122 and an output 124, is connected via its input to the intake tract 110, while an exhaust connection 1004 being adapted to be connected to the exhaust of the internal combustion engine 1000 via an electrically controlled disc separator 130, described hereafter.

[0068] The exhaust gas turbocharger 120 efficiently streams the supplied air into a feed line of the internal combustion engine 1000, the feed line being located downstream of the turbocharger 120 and comprising an air cooler 140, also called intercooler, as well as a throttle valve 150, the air cooler 140 and the throttle valve 150 being located downstream of the turbocharger 120.

[0069] The crankcase ventilation system 100 further incorporates at least one ventilation line 160 to connect the output 124 of the exhaust gas turbocharger 120 to the inlet 1002 of the internal combustion engine 1000. This ventilation line 160 enables a controlled air flow from the intake tract 110 to the inlet 1002 located downstream, optimizing the air-fuel mixture for the engine's operation.

[0070] Connected or adapted to be connected at an outlet 1004 of the internal combustion engine 1000, the crankcase ventilation system 100 further comprises an electrically driven disc separator 130, which is optionally equipped, with a flow control element 136. The flow control element 136 facilitates the ventilation of additional air through the ventilation lines 160 by directing this additional air to the input 122 of the exhaust gas turbocharger 120 located upstream.

[0071] In an embodiment, the inclusion of a speed monitor 132 and / or a pressure control valve 134 in the electrically driven disc separator 130 ensures precise control and monitoring of the ventilation process.

[0072] An example of electrically driven disc separator 130, comprising a speed monitor 132 and / or a pressure control valve 134, is an electrical Hydraulic Disk Separator, which is equivalent to an oil separator used for simulations and experiments, such as siltation tests. When in operation, results of the crankcase ventilation system 100 show significant improvement for hydrogen reduction in the blow-by gas compared to the use of simple Hydraulic Disk Separators.

[0073] When in operation, the electrically controlled disc separator 130 enables the creation of a vacuum within the crankcase. This vacuum facilitates proper ventilation of blow-by gases, containing hydrogen and water, promoting cleaner and more efficient engine operation. By creating a vacuum within the crankcase, it also extracts hot charge air from the boost air after the turbocharger compressor stage and before the charge air cooler. The hot charge air is then vented into the crankcase through the ventilation line(s). This ventilation line(s) is or are specifically routed below the cranktrain but above the oil level. Alternatively, it can be routed to other suitable insertion points within the ventilation system of the engine 1000.

[0074] Preferably, ventilation lines comprise aeration lines having a diameter of 5, 6 or 7 millimeters. For instance, two or three aeration lines can be provided, a first one having a diameter of 6 millimeters and not having a restrictor, while one or two additional aeration lines are used with the electrically driven disc separator 130 at the exhaust 1004 of the engine 1000 to significantly reduce the blow-by.

[0075] Tests can be conducted to evaluate the performance of the system 100 and / or to calibrate the latter. A siltation test, for instance, can be implemented to measure the hydrogen contents in standard cycles of the system 100 with different aeration variations

[0076] In addition, the crankcase ventilation system 100 can be configured so that hot charge air is extracted from the boost air after the turbocharger compressor stage 120 and before the charge air cooler stage 140.

[0077] Utilizing hot charge air rather than cold air in the crankcase ventilation system enables enhanced water absorption, effectively reducing water condensation within the combustion engine. This reduction in condensation helps mitigate oil dilution and the formation of white sludge, promoting cleaner and more efficient engine operation. Moreover, the adoption of hot charge air results in a significant decrease in the hydrogen content within the combustion engine, ensuring it consistently remains below the ignition limit of the hydrogen. It is noteworthy that using existing active oil mist separator in the system 100 obviates the need for additional vacuum pumps.

[0078] The use of hot charge air aeration enables to improve engine efficiency by minimizing water condensation. This approach effectively reduces water condensation within the combustion engine, which in turn mitigates oil dilution and prevents the formation of white sludge.

[0079] In addition, the adoption of hot charge air in the ventilation system significantly decreases the hydrogen content within the combustion engine. This ensures that the hydrogen content consistently remains below the hydrogen's ignition limit. Notably, existing active oil mist separator eliminates the need for an additional vacuum pump, simplifying the design of the system.

[0080] While cold air approaches usually require an additional vacuum pump to vent the gas into the crankcase, such approaches limit the efficiency of the system. However, relying on hot charge air enables offering a higher saturation grade, and significantly improving water absorption in the blow-by gas.

[0081] Preferably, the hot charge air is vented into the crankcase system 100 with a line routing below the crank train but remaining above the oil level of the engine 1000.

[0082] Reference is now made to Figure 3, which shows a flowchart of steps S10, S20, S30 and S40 of a method for operating a crankcase ventilation system according to an embodiment.

[0083] An initial step S10 comprises the installation of the crankcase ventilation system 100 on the internal combustion engine 1000, and more specifically, the connection of the output 124 of the exhaust gas turbocharger 120 to the feed line of the engine 1000, thereby connecting the output 124 of the exhaust gas turbocharger 120 to the inlet 1002 of the internal combustion engine 1000 using the at least one ventilation line 160 and also connecting the input 122 of the exhaust gas turbocharger 120 to the exhaust 1004 of the internal combustion engine 1000 using the electrically controlled disc separator 130.

[0084] The subsequent step S20 comprises the supplying of air to the crankcase ventilation system 100 using the intake tract 110. The intake tract 110 incorporates an air filter 115 that can be selected among different types, but in any case, is adapted to ensure efficient air filtration, preventing water condensation, and enhancing engine performance.

[0085] The other subsequent step S30 comprises the streaming of the supplied air into the feed line 140, 150 of the internal combustion engine 1000 using the gas turbocharger 120.

[0086] The other subsequent step S40 comprises the generation of a vacuum within the crankcase ventilation system by operating the electrically controlled disc separator 130. This is accomplished by operating the electrically controlled disc separator 130. The separator 130 effectively creates a vacuum within the crankcase, enabling the efficient extraction of hot charge air from the boost air after the turbocharger compressor stage and before the charge air cooler.

[0087] Although not illustrated, a step S35 may be comprised between the steps S30 and S40, corresponding to the ventilation of hot charge air through the ventilation line(s) with a flow rate, preferably below a given maximum, and using the crankcase ventilation system connected to the internal combustion engine 1000. Preferably, this maximum value is larger than 160 litres per minute and lower than 180 litres per minute, and preferably equal to 170 litres per minute.

[0088] In an embodiment, the steps S20, S30 (which may be followed by S35) and S40 can be carried out iteratively and repeatedly, in view of operating continuously the crankcase ventilation system.

[0089] It is apparent to those skilled in the art that the present disclosure and invention may be embodied in other specific forms without departing from essential features of the present disclosure. Accordingly, the aforementioned disclosure should not be construed as restrictive in all terms and should be exemplarily considered. The scope of the present disclosure should be determined by rational construing of the appended claims and all modifications within an equivalent scope of the present disclosure are included in the scope of the present disclosure and invention.

Claims

CLAIMS1. A crankcase ventilation system (100) for a internal combustion engine (1000), the crankcase ventilation system (100) comprising:- an intake tract (110) for supplying air to the crankcase ventilation system (100),- an exhaust gas turbocharger (120) having an input (122) connected to the intake tract (110), the input being adapted to be connected to an exhaust (1004) of the internal combustion engine (1000), the exhaust gas turbocharger (120) being adapted to stream the supplied air into a feed line (140, 150) of the internal combustion engine (1000),- at least one ventilation line (160) adapted to connect an output (124) of the exhaust gas turbocharger (120) to an inlet (1002) of the internal combustion engine (1000), and- an electrically controlled disc separator (130) adapted to connect the exhaust (1004) of the internal combustion engine (1000) to the intake tract (110) and to the input (122) of the exhaust gas turbocharger (120) wherein the supplied air which is streamed by the exhaust gas turbocharger (120) into the feed line (140, 150) of the internal combustion engine (1000) is hot charge air.

2. The crankcase ventilation system (100) according to claim 1 , wherein the intake tract (110) comprises an air filter (115), the air filter (115) being selected among a hydrophobic filter, a photocatalytic filter, and a nano-fiber filter.

3. The crankcase ventilation system according to claim 1 or 2, wherein the at least one ventilation line (160) consists of a single line, called first aeration line, the first aeration line having a diameter selected among 4 millimetres, 5 millimetres, 6 millimetres, 7 millimetresand 8 millimetres.

4. The crankcase ventilation system according to claim 1 or 2, wherein the at least one ventilation line (160) comprises a plurality of lines, called aeration lines, each of the aeration lines having a diameter selected among 4 millimetres, 5 millimetres, 6 millimetres, 7 millimetres and 8 millimetres.

5. The crankcase ventilation system according to any of the preceding claims, wherein the at least one ventilation line (160) comprises a throttle and / or a restrictor.

6. The crankcase ventilation system according to any of the preceding claims, wherein the electrically controlled disc separator (130) comprises a flow control element (136).

7. The crankcase ventilation system according to claim 6, wherein the electrically controlled disc separator (130) and the flow control element (136) are configured to ventilate additional air through the at least one ventilation line (160) with a maximum flow value which is larger than 160 litres per minute and lower than 180 litre per minute, and which is preferably equal to 170 litres per minute.

8. The crankcase ventilation system according to claim 6 or 7, wherein the electrically controlled disc separator (130) further comprises a speed monitor (132) and / or a pressure control valve (134).

9. A internal combustion engine, comprising the crankcase ventilation system (100) according to any of the preceding claims.

10. A method for operating the crankcase ventilation system (100) according to any of the preceding claims, comprising: a) connecting (S10) the output (124) of the exhaust gas turbocharger (120) to the feed line (140, 150) of the internal combustion engine (1000), connecting the output (124) of the exhaust gas turbocharger (120) to the inlet (1002) of the internal combustion engine(1000) using the at least one ventilation line (160) and also connecting the input (122) of the exhaust gas turbocharger (120) to the exhaust (1004) of the internal combustion engine (1000) using the electrically controlled disc separator (130), b) supplying (S20) air to the crankcase ventilation system (100) using the intake tract (110); c) streaming (S30) the supplied air into the feed line (140, 150) of the internal combustion engine (1000) using the gas turbocharger (120), and d) generating (S40) a vacuum within the crankcase ventilation system by operating the electrically controlled disc separator (130).

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