Breather system for a crankcase

Abstract

The invention relates to a breather system (10) for a crankcase (102) of an internal combustion engine (100) which can be operated with a gaseous fuel, in particular for a crankcase (102) of a hydrogen combustion engine, in which breather system (10) leakage gas which contains the fuel and / or reaction products of the fuel passes during the combustion operation into the crankcase (102). The breather system comprises a leakage gas discharge line (14) for discharging a ventilation gas which is introduced into the crankcase (102) and gas mixture (G) which includes leakage gas from the crankcase (102), and one or more flow setting devices (16a, 16b) for setting the volumetric flow of the ventilation gas which is introduced into the crankcase (102) and / or the volumetric flow of the gas mixture (G) which is discharged from the crankcase (102), wherein a flow setting device (16a) is in the form of a centrifugal separator, in particular as a disc separator, for conveying the discharged gas mixture (G) through the leakage gas discharge line (14).

Description

[0001] Crankcase ventilation system

[0002] The invention relates to a ventilation system for a crankcase of an internal combustion engine operable with a gaseous fuel, in which leakage gas containing the fuel and / or reaction products of the fuel enters the crankcase during the combustion process. The ventilation system comprises a leakage gas discharge line for discharging a gas mixture comprising a ventilation gas introduced into the crankcase and leakage gas from the crankcase, and one or more flow adjustment devices for adjusting the volume flow of the ventilation gas introduced into the crankcase and / or the volume flow of the gas mixture discharged from the crankcase. One flow adjustment device is designed as a centrifugal separator, in particular as a disc separator, for conveying the discharged gas mixture through the leakage gas discharge line.

[0003] The invention further relates to an internal combustion engine which can be operated with a gaseous fuel, wherein the internal combustion engine comprises a crankcase and a ventilation system for the crankcase.

[0004] Furthermore, the invention relates to a method for venting a crankcase of an internal combustion engine operable with a gaseous fuel, in which leakage gas containing the fuel and / or reaction products of the fuel enters the crankcase during the combustion process, by means of a ventilation system, comprising the steps of: discharging a gas mixture comprising a ventilation gas introduced into the crankcase and leakage gas from the crankcase via a leakage gas discharge line of the ventilation system and adjusting the volume flow of the ventilation gas introduced into the crankcase and / or the volume flow of the gas mixture discharged from the crankcase by means of one or more flow adjustment devices of the ventilation system, wherein a flow adjustment device is designed as a centrifugal separator, in particular as a disc separator, for conveying the discharged gas mixture through the leakage gas discharge line.

[0005] Crankcase ventilation requires the introduction of a ventilation gas into the crankcase so that a gas mixture comprising the ventilation gas and the leakage gas can be discharged from the crankcase. Current technology uses disc separators, for example, to generate the flow.

[0006] US Pat. No. 7,152,589 B2 discloses a crankcase ventilation system in which the speed of a disc separator is controlled depending on the pressure in the crankcase. This allows the pressure in the crankcase to be kept constant.

[0007] Furthermore, internal combustion engines that can be operated with a gaseous fuel are known from the prior art. For example, the document DE 10 2021 133 918 A1 discloses a ventilation system for a crankcase of such an internal combustion engine.

[0008] In internal combustion engines powered by gaseous fuel, neither the fuel nor its reaction products may be allowed to accumulate in the crankcase or in the leakage gas vent line, as the gas mixture to be vented is highly flammable and explosive if the quantity and / or concentration of the fuel and / or reaction products is too high. To ensure the safe operation of internal combustion engines powered by gaseous fuel, it must be ensured that no highly flammable and explosive gas mixture flows through the crankcase and its ventilation system. To ensure the safe operation of an internal combustion engine, it may also be necessary to prevent excessive accumulation of water vapor in the crankcase. This water can mix with the engine oil, impairing its lubricating properties.Furthermore, the water can freeze, which can also cause damage to the combustion engine.

[0009] The object underlying the invention is therefore to increase the safety during operation of an internal combustion engine with a crankcase ventilation system that can be operated with a gaseous fuel.

[0010] The object is achieved by a ventilation system of the type mentioned at the outset, wherein the ventilation system according to the invention has a control device which is designed to control the one or more flow adjustment devices as a function of a quantity and / or concentration of the fuel and / or the reaction products in at least one region of the ventilation system in order to change the volume flow of the ventilation gas introduced into the crankcase and / or to change the volume flow of the gas mixture discharged from the crankcase.

[0011] By varying the volume flow of the ventilation gas introduced into the crankcase and / or varying the volume flow of the gas mixture discharged from the crankcase, fuel and / or fuel reaction products are prevented from accumulating within the crankcase and / or the leakage gas discharge line, thereby preventing the formation of a highly flammable and explosive gas mixture and / or excessive dilution of the engine oil with water. By controlling the one or more flow adjustment devices, the flow velocity and volume flow in the crankcase and in the leakage gas discharge line can be increased, thereby accelerating the discharge of the gas mixture comprising the leakage gas. By controlling the one or more flow adjustment devices, the ventilation or venting of the crankcase can be increased as needed.The ventilation system can therefore effectively remove, for example, highly flammable and explosive gas mixtures and / or moisture. The ventilation system according to the invention thus ensures the safe operation of an internal combustion engine powered by a gaseous fuel.

[0012] The fuel can be, for example, hydrogen, methane (CH ) or ammonia (NH3). The reaction products can be nitrogen oxides (NO X ), carbon monoxide (CO) or water vapor.

[0013] A flow adjustment device is designed as a centrifugal separator, in particular as a disc separator, for conveying the discharged gas mixture through the leakage gas discharge line. The control device is preferably configured to control the conveying capacity of the centrifugal separator as a function of a quantity and / or concentration of the fuel and / or the reaction products in the at least one region of the ventilation system. By adjusting the conveying capacity, the flow velocity and / or the volume flow in the leakage gas discharge line can be increased, so that the discharge of the gas mixture comprising the leakage gas is accelerated. By adjusting the conveying capacity, the ventilation or venting of the crankcase can be increased. The centrifugal separator can be driven, in particular hydraulically, pneumatically and / or electrically.

[0014] Alternatively, the centrifugal separator can be

[0015] Flow adjustment device can also be a different conveying direction for conveying the discharged gas mixture through the leakage gas discharge line.

[0016] The centrifugal separator can comprise a conveyor rotor equipped with multiple separation elements. The separation elements can be separation plates stacked to form a plate stack. In addition to the conveying function, the centrifugal separator or plate separator thus also performs a separation function. The centrifugal separator, which can be designed as a plate separator, is preferably configured to separate liquid particles, for example oil particles, from the gas mixture discharged from the crankcase. In a preferred embodiment of the ventilation system according to the invention, the centrifugal separator has a conveyor drive configured to rotate a conveyor rotor of the centrifugal separator. The control device is preferably configured to control the conveying capacity of the centrifugal separator by setting a rotational speed on the conveyor drive.The speed of the conveyor drive can be adjusted, for example, by controlling the drive power.

[0017] In a further preferred embodiment of the ventilation system according to the invention, a flow adjustment device is designed as a ventilation valve for adjusting the volume flow of the ventilation gas introduced into the crankcase. The control device is preferably configured to adjust the ventilation valve depending on a quantity and / or concentration of the fuel and / or the reaction products in the at least one region of the ventilation system. Adjusting the ventilation system can, for example, involve changing the flow cross-section of the ventilation valve. The ventilation gas can be exhaust gas. In this case, the crankcase is ventilated with exhaust gas from an exhaust line coming from the combustion chambers of the internal combustion engine. The ventilation gas can also be fresh air. In this case, the crankcase is ventilated with fresh air from an intake line leading to the combustion chambers of the internal combustion engine.

[0018] Furthermore, a ventilation system according to the invention is preferred, which comprises a ventilation line for introducing the ventilation gas into the crankcase, wherein the ventilation valve is preferably arranged on the ventilation line. The ventilation line is preferably a high-pressure line located downstream of a compressor of an exhaust gas turbocharger of the internal combustion engine, or a low-pressure line located upstream of a compressor of an exhaust gas turbocharger of the internal combustion engine, in the direction of flow. A suitable pressure reduction can then be achieved via the ventilation valve, so that the intended amount of ventilation gas is introduced into the crankcase.In a further preferred embodiment, the ventilation system according to the invention has at least one measuring device which is designed to measure the quantity and / or concentration of the fuel and / or the reaction products in the at least one region, wherein the control device is preferably designed to control the one or more flow adjustment devices as a function of the quantity and / or concentration of the fuel and / or the reaction products measured by the measuring device in the at least one region of the ventilation system in order to change the volume flow of the ventilation gas introduced into the crankcase and / or to change the volume flow of the gas mixture discharged from the crankcase.For example, the control device is configured to control the conveying capacity of the centrifugal separator as a function of the quantity and / or concentration of the fuel and / or the reaction products in the at least one region of the ventilation system measured by the measuring device. For example, the control device is configured to adjust the venting valve as a function of the quantity and / or concentration of the fuel and / or the reaction products in the at least one region of the ventilation system measured by the measuring device. The at least one measuring device can be configured to measure the quantity and / or concentration of hydrogen, methane, ammonia, nitrogen oxides and / or carbon monoxide or the humidity, in particular the relative humidity, in the at least one region.The at least one measuring device can be a hydrogen sensor, a methane sensor, an ammonia sensor, a nitrogen oxide sensor, a carbon monoxide sensor or a humidity sensor.

[0019] In a further preferred embodiment, the ventilation system according to the invention has a data processing device which is configured to calculate the quantity and / or concentration of the fuel and / or the reaction products for the at least one region, wherein the control device is configured to control the one or more flow adjustment devices as a function of the quantity and / or concentration of the fuel and / or the reaction products calculated by the data processing device for the at least one region of the ventilation system in order to change the volume flow of the ventilation gas introduced into the crankcase and / or to change the volume flow of the gas mixture discharged from the crankcase. The data processing device preferably uses a calculation data set to calculate the quantity and / or concentration of the fuel and / or the reaction products.The calculation data set may, for example, include operating parameters of the ventilation system and / or the combustion engine. The calculation data set may further include ventilation system-specific system parameters and / or combustion engine-specific engine parameters.

[0020] In a further preferred embodiment of the ventilation system according to the invention, at least one measuring device is arranged in the crankcase. Alternatively or additionally, at least one measuring device is arranged in a flow adjustment device. Alternatively or additionally, at least one measuring device is arranged on the leakage gas discharge line. Alternatively or additionally, at least one measuring device is arranged on an intake line leading to combustion chambers of the internal combustion engine. Alternatively or additionally, at least one measuring device is arranged on an exhaust line coming from combustion chambers of the internal combustion engine. At least one measuring device can be arranged in the centrifugal separator. At least one measuring device can be arranged upstream or downstream of the centrifugal separator in the flow direction of the gas mixture comprising the leakage gas. The at least one measuring device can be arranged in or on the ventilation valve.

[0021] At least one region in which the quantity and / or concentration of the fuel and / or the reaction products is measured and / or for which the quantity and / or concentration of the fuel and / or the reaction products is calculated is preferably located in the crankcase, in a flow adjustment device, in the leakage gas discharge line, in an intake line leading to combustion chambers of the internal combustion engine, or in an exhaust line coming from combustion chambers of the internal combustion engine. At least one region in which the quantity and / or concentration of the fuel and / or the reaction products is measured and / or for which the quantity and / or concentration of the fuel and / or the reaction products is calculated can be located in the centrifugal separator.At least one region in which the quantity and / or concentration of the fuel and / or the reaction products is measured and / or for which the quantity and / or concentration of the fuel and / or the reaction products is calculated can be located upstream or downstream of the centrifugal separator in the flow direction of the gas mixture comprising the leakage gas. At least one region in which the quantity and / or concentration of the fuel and / or the reaction products is measured and / or for which the quantity and / or concentration of the fuel and / or the reaction products is calculated can be located in or on the vent valve.

[0022] In another preferred embodiment of the venting system according to the invention, the control device is configured to control the one or more flow adjustment devices as a function of the quantity and / or concentration of the fuel and / or the reaction products in the at least one region of the venting system if the quantity and / or concentration of the fuel and / or the reaction products in the at least one region of the venting system exceeds a limit value. Alternatively or additionally, the control device is configured to control the one or more flow adjustment devices independently of the quantity and / or concentration of the fuel and / or the reaction products in the at least one region of the venting system if the quantity and / or concentration of the fuel and / or the reaction products in the at least one region of the venting system falls below a limit value.For hydrogen, for example, the limit value can be in a range between 5% and 30%, in particular around 10%. For ammonia, for example, the limit value can be in a range between 1% and 10%, in particular around 4%.

[0023] Furthermore, a ventilation system according to the invention is preferred in which the control device is configured to control the one or more flow adjustment devices as a function of the pressure in the crankcase and / or a required media separation. When controlling the one or more flow adjustment devices, the pressure in the crankcase and / or the required media separation are taken into account in addition to the quantity and / or concentration of the fuel and / or the reaction products in the at least one region of the ventilation system. The required media separation can relate to the required oil mist separation.

[0024] The object underlying the invention is further achieved by an internal combustion engine of the type mentioned at the outset, wherein the ventilation system of the internal combustion engine according to the invention is designed according to one of the embodiments described above. With regard to the advantages and modifications of the internal combustion engine according to the invention, reference is made to the advantages and modifications of the ventilation system according to the invention. During operation of the internal combustion engine, the ventilation system makes it possible to avoid shutting down the internal combustion engine, since a critical quantity and / or concentration of the fuel and / or the reaction products is not exceeded due to the demand-based ventilation. In particular, if the internal combustion engine is an industrial engine, a cost-intensive interruption of a work process can thus be avoided.

[0025] The object underlying the invention is further achieved by a method of the type mentioned at the outset, wherein, within the scope of the method according to the invention, a control device of the ventilation system controls the one or more flow adjustment devices as a function of a quantity and / or concentration of the fuel and / or the reaction products in at least one region of the ventilation region to change the volume flow of the ventilation gas introduced into the crankcase and / or to change the volume flow of the gas mixture discharged from the crankcase. The method according to the invention is preferably carried out with a ventilation system according to one of the embodiments described above. With regard to the advantages and modifications of the method according to the invention, reference is therefore first made to the advantages and modifications of the ventilation system according to the invention.

[0026] A flow adjustment device is designed as a centrifugal separator, in particular as a disc separator, for conveying the discharged gas mixture through the leakage gas discharge line, wherein the control device preferably controls the conveying capacity of the centrifugal separator as a function of a quantity and / or concentration of the fuel and / or the reaction products in at least one region of the ventilation system. The control device preferably causes an increase in the conveying capacity of the centrifugal separator when the quantity and / or concentration of the fuel and / or the reaction products increases. Alternatively or additionally, the control device causes a reduction in the conveying capacity of the centrifugal separator when the quantity and / or concentration of the fuel and / or the reaction products decreases.Preferably, a flow adjustment device is designed as a ventilation valve for adjusting the volume flow of the ventilation gas introduced into the crankcase, wherein the control device preferably adjusts the ventilation valve depending on a quantity and / or concentration of the fuel and / or the reaction products in at least one region of the ventilation system. Preferably, the control device causes an increase in the free flow cross-section of the ventilation valve when the quantity and / or concentration of the fuel and / or the reaction products increases. Alternatively or additionally, the control device causes a reduction in the free flow cross-section of the ventilation valve when the quantity and / or concentration of the fuel and / or the reaction products decreases.

[0027] Alternatively, the flow adjustment device designed as a centrifugal separator can also be a different conveying direction for conveying the discharged gas mixture through the leakage gas discharge line.

[0028] In a further preferred embodiment of the method according to the invention, the quantity and / or concentration of the fuel and / or the reaction products in the at least one region is measured by means of at least one measuring device of the venting system. Alternatively or additionally, the quantity and / or concentration of the fuel and / or the reaction products for the at least one region is calculated by means of a data processing device of the venting system.

[0029] Preferred embodiments of the invention are explained and described in more detail below with reference to the accompanying drawings.

[0030] Fig. 1 shows an internal combustion engine according to the invention in a schematic representation;

[0031] Fig. 2 shows a further internal combustion engine according to the invention in a schematic representation; and

[0032] Fig. 3 shows a further internal combustion engine according to the invention in a schematic representation.

[0033] Fig. 1 shows an internal combustion engine 100, which is operable with a gaseous fuel, namely hydrogen. The internal combustion engine 100 comprises a crankcase 102 and a ventilation system 10 for the crankcase 102. An air-hydrogen mixture is combusted in the combustion chambers 104a-104d of the internal combustion engine 100. During the internal combustion engine operation, a leakage gas enters the crankcase 102, wherein the leakage gas contains the fuel, i.e., hydrogen, and reaction products of the fuel, for example, nitrogen oxides (NO X ), carbon monoxide (CO) or water vapor.

[0034] The internal combustion engine 100 comprises an intake line 106, which is divided by a compressor 110 of an exhaust gas turbocharger 108 into a low-pressure region 112 and a high-pressure region 114. The intake line 106 leads to the combustion chambers 104a-104d of the internal combustion engine 100, so that fresh air F for the combustion process is supplied to the combustion chambers 104a-104d via the intake line 106. The exhaust gas A produced during the combustion process is discharged from the combustion chambers 104a-104d of the internal combustion engine 100 via an exhaust line 116. A turbine 118 of the exhaust gas turbocharger 108 divides the exhaust line 116 into a high-pressure region 120 and a low-pressure region 122.

[0035] The ventilation system 10 comprises a ventilation line 12 for introducing a ventilation gas into the crankcase 102. The ventilation line 12 is a low-pressure line connected to the low-pressure region 112 of the intake line 106. The ventilation gas used by the ventilation system 10 for crankcase ventilation is, in this case, fresh air F. The crankcase 102 is ventilated with fresh air F from an intake line 106 leading to the combustion chambers 104a-104d of the internal combustion engine 100.

[0036] The ventilation system 10 further comprises a leakage gas discharge line 14 for discharging a gas mixture G from the crankcase 102. The gas mixture G comprises the ventilation gas introduced into the crankcase 102 and the leakage gas that entered the crankcase 102 during the combustion process.

[0037] The leakage gas discharge line 14 leads to a flow adjustment device 16a. The flow adjustment device 16a serves to adjust the volume flow of the ventilation gas introduced into the crankcase 102 and the volume flow of the gas mixture G discharged from the crankcase 102. The flow adjustment device 16a is a conveying device for conveying the discharged gas mixture G through the leakage gas discharge line 14. Specifically, the flow adjustment device 16a is a centrifugal separator, namely a disc separator, which, in addition to a conveying function, also performs a separation function. The flow adjustment device 16a, designed as a disc separator, serves to separate oil particles from the gas mixture G, wherein the separated oil particles are guided back into the crankcase 102 of the internal combustion engine 100 via the oil return line 20.

[0038] The flow adjustment device 16a designed as a disc separator has a

[0039] Conveyor drive 18, via which the delivery rate of the flow adjustment device 16a can be adjusted. A gas return line 22 is connected to the flow adjustment device 16a, via which the gas mixture G is conveyed back into the low-pressure region 112 of the intake line 106.

[0040] The ventilation system 24 further comprises a control device 24 which controls the flow adjustment device 16a, designed as a disc separator, as a function of a quantity and / or concentration of the fuel, i.e., hydrogen, and / or the reaction products in at least one region B1-B5 of the ventilation system 10 to change the volume flow of the ventilation gas introduced into the crankcase 102 and to change the volume flow of the gas mixture G discharged from the crankcase 102. When controlling the flow adjustment device 16a, the control device 24 can take into account the quantity and / or concentration of the fuel and / or the reaction products in one or more regions B1-B5.

[0041] The control device 24 is configured to control the delivery rate of the flow adjustment device 16a, designed as a disc separator, as a function of the quantity and / or concentration of the fuel or the reaction products in one or more areas B1-B5. By adjusting the delivery rate, the flow velocity and the volume flow in the leakage gas discharge line 14 can be increased, so that the discharge of the gas mixture G comprising the leakage gas is accelerated. By adjusting the delivery rate, the ventilation or deaeration of the crankcase 102 can be increased. The control device 24 is configured to control the delivery rate of the delivery device by setting a speed on the delivery drive 18. The delivery drive 18 is an electric motor.

[0042] The ventilation system 10 can have one or more measuring devices 26a-26e, wherein the one or more measuring devices 26a-26e measure the quantity and / or concentration of the fuel and / or the reaction products in a range B1-B5. The ventilation system 10 can comprise one or more of the illustrated measuring devices 26a-26e. The control device 24 is thus configured to control the flow adjustment device 16a depending on the quantity and / or concentration of the fuel and / or the reaction products in a range B1-B5 of the ventilation system measured by one or more measuring devices 26a-26e, in order to change the volume flow of the ventilation gas introduced into the crankcase 102 and / or to change the volume flow of the gas mixture G discharged from the crankcase 102.The measuring devices 26a-26e can be configured to measure the quantity and / or concentration of hydrogen, methane, and / or ammonia in the area B1-B5 assigned to the respective measuring device 26a-26e. For example, a hydrogen sensor, a methane sensor, an ammonia sensor, a nitrogen oxide sensor, a carbon monoxide sensor, or a humidity sensor can be used as the measuring device 26a-26e.

[0043] Alternatively or in addition to the one or more measuring devices 26a-26e, the venting system 10 can also include a data processing device configured to calculate the quantity and / or concentration of the fuel and / or the reaction products in one or more BIBS areas. The control device then controls the flow adjustment device 16a, designed as a disc separator, depending on the calculated quantity and / or concentration of the fuel and / or the reaction products.

[0044] The control device 24 causes an increase in the delivery rate of the flow adjustment device 16a, designed as a disc separator, when the quantity and / or concentration of the fuel and / or the reaction products increases. Furthermore, the control device 24 causes a decrease in the delivery rate of the flow adjustment device 16a, designed as a disc separator, when the quantity and / or concentration of the fuel and / or the reaction products decreases.

[0045] Fig. 1 shows exemplary possible positions of the measuring devices 26a-26e. The measuring device 26a is arranged in the crankcase 102. The measuring device 26b is arranged on the leakage gas discharge line 14. The measuring device 26c is arranged in the flow adjustment device 16a, which is designed as a disc separator. The measuring device 26d is arranged on the gas return line 22. The measuring device 26e is arranged on the intake line 106 leading to the combustion chambers 104a-104d of the internal combustion engine 100.

[0046] In the internal combustion engine 100 shown in Fig. 2, the ventilation line 12 of the ventilation system 10 is connected to the high-pressure region 114 of the intake line 106.

[0047] The ventilation system 10 further comprises a flow adjustment device 16b, designed as a ventilation valve, for adjusting the volume flow of the ventilation gas introduced into the crankcase 102. The flow adjustment device 16b, designed as a ventilation valve, is arranged on the ventilation line 12. The ventilation line 12 is a high-pressure line located downstream of the compressor 110 of the exhaust gas turbocharger 108 in the flow direction of the fresh air F.

[0048] The control device 24 is configured to adjust the flow adjustment device 16b, which is designed as a vent valve, depending on a quantity and / or concentration of the fuel and / or the reaction products in a region B1-B5 of the venting system 10. Adjusting the vent valve can, for example, involve changing the free flow cross-section of the vent valve 16b.

[0049] The ventilation and venting of the crankcase 102 can thus be achieved by controlling the flow adjustment device 16a, which is designed as a disc separator, and by controlling the flow adjustment device 16b, which is designed as a ventilation valve. Preferably, the control device 24 coordinates the operating states of the flow adjustment devices 16a, 16b.

[0050] In the internal combustion engine 100 shown in Fig. 3, the ventilation system 10 also includes two flow adjustment devices 16a, 16b. The flow adjustment device 16a is a disc separator. The flow adjustment device 16b is a vent valve. The vent line 12 for introducing the vent gas into the crankcase 102 is, in this case, connected to the high-pressure region 120 of the exhaust line 116. The flow adjustment device 16b, designed as a vent valve, is arranged on the vent line 12. The vent line 12 is thus a high-pressure line located upstream of the turbine 118 of the exhaust gas turbocharger 108 in the flow direction of the exhaust gas A. The ventilation gas in this case is exhaust gas A. The crankcase 102 is thus ventilated with exhaust gas A from the exhaust line 116 coming from the combustion chambers 104a-104d of the internal combustion engine 100.

[0051] The control devices 24 of the illustrated venting systems 10 can be configured to control the flow adjustment devices 16a, 16b depending on the quantity and / or concentration of the fuel and / or the reaction products in the venting system 10 if the quantity and / or concentration of the fuel and / or the reaction products exceeds a limit value. Furthermore, the control devices 24 can be configured to control the flow adjustment devices 16a, 16b independently of the quantity and / or concentration of the fuel and / or the reaction products in the venting system 10 if the quantity and / or concentration of the fuel and / or the reaction products falls below a limit value.Furthermore, the control devices 24 can be configured to control the flow adjustment devices 16a, 16b also as a function of the pressure in the crankcase 102 and / or a required media separation, for example a required oil mist separation.

[0052] Reference symbol

[0053] 10 Ventilation system

[0054] 12 Ventilation line

[0055] 14 Leakage gas discharge line

[0056] 16a, 16b Flow adjustment devices

[0057] 18 Conveyor drive

[0058] 20 Oil return line

[0059] 22 Gas return line

[0060] 24 Control device

[0061] 26a-26e Measuring devices

[0062] 100 combustion engine

[0063] 102 Crankcase

[0064] 104a-104d Combustion chambers

[0065] 106 intake line

[0066] 108 exhaust gas turbochargers

[0067] 110 compressors

[0068] 112 Low pressure range

[0069] 114 High pressure area

[0070] 116 exhaust pipe

[0071] 118 Turbine

[0072] 120 high pressure area

[0073] 122 Low pressure range

[0074] A exhaust

[0075] B1-B5 areas

[0076] G gas mixture

[0077] F Fresh air

Claims

Claims Ventilation system (10) for a crankcase (102) of an internal combustion engine (100) operable with a gaseous fuel, in particular for a crankcase (102) of a hydrogen internal combustion engine, in which leakage gas containing the fuel and / or reaction products of the fuel enters the crankcase (102) during the combustion process, with a leakage gas discharge line (14) for discharging a gas mixture (G) comprising a ventilation gas and leakage gas introduced into the crankcase (102) from the crankcase (102);and one or more flow adjustment devices (16a, 16b) for adjusting the volume flow of the ventilation gas introduced into the crankcase (102) and / or the volume flow of the gas mixture (G) discharged from the crankcase (102), wherein a flow adjustment device (16a) is designed as a centrifugal separator, in particular as a disc separator, for conveying the discharged gas mixture (G) through the leakage gas discharge line (14);characterized by a control device (24) which is configured to control the one or more flow adjustment devices (16a, 16b) as a function of a quantity and / or concentration of the fuel and / or the reaction products in at least one region (B1-B5) of the ventilation system (10) in order to change the volume flow of the ventilation gas introduced into the crankcase (102) and / or to change the volume flow of the gas mixture (G) discharged from the crankcase (102). Ventilation system (10) according to claim 1, characterized in that the control device (24) is configured to control the conveying capacity of the centrifugal separator as a function of a quantity and / or concentration of the fuel and / or; of the reaction products in the at least one region (B1-B5) of the venting system (10). Venting system (10) according to claim 1 or 2, characterized in that the centrifugal separator (16a) has a conveyor drive (18) configured to drive a conveyor rotor of the centrifugal separator in rotation, wherein the control device (24) is configured to control the conveying capacity of the centrifugal separator by setting a rotational speed on the conveyor drive (18).Ventilation system (10) according to one of the preceding claims, characterized in that a flow adjustment device (16b) is designed as a ventilation valve for adjusting the volume flow of the ventilation gas introduced into the crankcase (102), wherein the control device (24) is preferably configured to adjust the ventilation valve depending on a quantity and / or concentration of the fuel and / or the reaction products in the at least one region (B1-B5) of the ventilation system (10). Ventilation system (10) according to claim 4, characterized by a ventilation line (12) for introducing the ventilation gas into the crankcase (102), wherein the ventilation valve is preferably arranged on the ventilation line (12).Ventilation system (10) according to one of the preceding claims, characterized by at least one measuring device (26a-26e) which is designed to measure the quantity and / or concentration of the fuel and / or the reaction products in the at least one region (B1-B5), wherein the control device (24) is designed to control the one or more flow adjustment devices (16a, 16b) as a function of the quantity and / or concentration measured by the measuring device (26a-26e). Concentration of the fuel and / or the reaction products in the at least one region (B1-B5) of the ventilation system (10) to change the volume flow of the ventilation gas introduced into the crankcase (102) and / or to change the volume flow of the gas mixture (G) discharged from the crankcase (102).Ventilation system (10) according to one of the preceding claims, characterized by a data processing device which is configured to calculate the quantity and / or concentration of the fuel and / or the reaction products for the at least one region (B1-B5), wherein the control device (24) is configured to control the one or more flow adjustment devices (16a, 16b) as a function of the quantity and / or concentration of the fuel and / or the reaction products for the at least one region (B1-B5) of the ventilation system (10) calculated by the data processing device, in order to change the volume flow of the ventilation gas introduced into the crankcase (102) and / or to change the volume flow of the gas mixture (G) discharged from the crankcase (102).Ventilation system (10) according to claim 6 or 7, characterized in that the at least one measuring device (26a-26e) is arranged in the crankcase (102), in a flow adjustment device (16a, 16b), on the leakage gas discharge line (14), on an intake line (106) leading to combustion chambers (104a-104d) of the internal combustion engine (100) or on an exhaust line (116) coming from combustion chambers (104a-104d) of the internal combustion engine (100); and / or the at least one region (B1-B5) in which the quantity and / or concentration of the fuel and / or the. Reaction products are measured and / or for which the quantity and / or concentration of the fuel and / or the reaction products is calculated, is located in the crankcase (102), in a flow adjustment device (16a, 16b), in the leakage gas discharge line (14), in an intake line (106) leading to combustion chambers (104a-104d) of the internal combustion engine (100) or in an exhaust line (116) coming from combustion chambers (104a-104d) of the internal combustion engine (100).The venting system (10) according to one of the preceding claims, characterized in that the control device (24) is configured to control the one or more flow adjustment devices (16a, 16b) as a function of the quantity and / or concentration of the fuel and / or the reaction products in the at least one region (B1-B5) of the venting system (10) when the quantity and / or concentration of the fuel and / or the reaction products in the at least one region (B1-B5) of the venting system (10) exceeds a limit value; and / or to control the one or more flow adjustment devices (16a, 16b) independently of the quantity and / or concentration of the fuel and / or the reaction products in the at least one region (B1-B5) of the venting system (10) when the quantity and / or concentration of the fuel and / or the reaction products in the at least one region (B1-B5) of the venting system (10) falls below a limit value.Ventilation system (10) according to one of the preceding claims, characterized in that the control device (24) is designed to control the one or more flow adjustment devices (16a, 16b) as a function of the pressure in the crankcase (102) and / or a required media separation. An internal combustion engine (100) operable with a gaseous fuel, comprising a crankcase (102); and a ventilation system (10) for the crankcase (102); characterized in that the ventilation system (10) is designed according to one of the preceding claims. A method for venting a crankcase (102) of an internal combustion engine (100) operable with a gaseous fuel, in particular a crankcase (102) of a hydrogen internal combustion engine, in which leakage gas containing the fuel and / or reaction products of the fuel enters the crankcase (102) during the combustion process, by means of a ventilation system (10), in particular a ventilation system (10) according to one of claims 1 to 10, comprising the steps: Discharging a gas mixture (G) comprising a ventilation gas and leakage gas introduced into the crankcase (102) from the crankcase (102) via a leakage gas discharge line (14) of the ventilation system (10); and Adjusting the volume flow of the ventilation gas introduced into the crankcase (102) and / or the volume flow of the gas mixture (G) discharged from the crankcase (102) by means of one or more flow adjustment devices (16a, 16b) of the ventilation system (10), wherein a flow adjustment device (16a) is designed as a centrifugal separator, in particular as a disc separator, for conveying the discharged gas mixture (G) through the leakage gas discharge line (14); characterized in that a control device (24) of the ventilation system (10) controls the one or more flow adjustment devices (16a, 16b) depending on a quantity and / or concentration of the fuel and / or the reaction products in at least one region (B1-B5) of the ventilation system (10) to change the volume flow of the gas mixture (G) discharged into the crankcase (102) introduced ventilation gas and / or for changing the volume flow of the gas mixture (G) discharged from the crankcase (102).

13. The method according to claim 12, characterized in that the control device (24) controls the conveying capacity of the centrifugal separator as a function of a quantity and / or concentration of the fuel and / or the reaction products in at least one region (B1-B5) of the ventilation system (10); and / or a flow adjustment device (16b) is designed as a ventilation valve for adjusting the volume flow of the ventilation gas introduced into the crankcase (102), wherein the control device (24) preferably adjusts the ventilation valve as a function of a quantity and / or concentration of the fuel and / or the reaction products in at least one region (B1-B5) of the ventilation system (10).

14. Method according to claim 12 or 13, characterized by at least one of the following steps: Measuring the quantity and / or concentration of the fuel and / or the reaction products in the at least one region (B1-B5) by means of at least one measuring device (26a-26e) of the ventilation system (10); Calculating the quantity and / or concentration of the fuel and / or the reaction products for the at least one region (B1-B5) by means of a data processing device of the ventilation system (10).

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