Method for Operating an Internal Combustion Engine of a Motor Vehicle

Abstract

A method for operating an internal combustion engine of a motor vehicle. The internal combustion engine includes a combustion chamber, an intake tract, a compressor disposed in the intake tract, and a conduit element which is fluidly connected to the intake tract. The internal combustion engine is operable in a heating mode to heat at least a compressor housing of the compressor. In the heating mode a part of the air flowing through the intake tract and compressed by the compressor is returned to the intake tract by the conduit element. The method includes recording a temperature of the air in the intake tract upstream of the compressor by a sensor and comparing the temperature with a threshold value. When the temperature is lower than the threshold value, the internal combustion engine is operated in the heating mode.

Claims

1-8. (canceled)

9. A method for operating an internal combustion engine (10) of a motor vehicle, the internal combustion engine (10) comprising: a combustion chamber; an intake tract (20), wherein air is flowable through the intake tract (20) and wherein the combustion chamber is providable with the air via the intake tract (20); a compressor (24) disposed in the intake tract (20), wherein the compressor (24) has a compressor housing (32) and a compressor wheel (28) disposed rotatably in the compressor housing (32) for compressing air flowing through the intake tract (20) and to the combustion chamber; and a conduit element (36) which is fluidly connected to the intake tract (20) at a first connection point (V1) disposed upstream of the compressor wheel (28) and at a second connection point (V2) disposed downstream of the compressor wheel (28); wherein the internal combustion engine (10) is operable in a heating mode to heat at least the compressor housing (32) and wherein in the heating mode at least a part of the air flowing through the intake tract (20) and compressed by the compressor wheel (28) is removed from the intake tract (20) at the second connection point (V2), introduced into the conduit element (36), provided to the first connection point (V1) by the conduit element (36) and introduced into the intake tract (20) at the first connection point (V1); and comprising the steps of: recording a temperature of the air in the intake tract (20) upstream of the compressor wheel (28) by a sensor; comparing the temperature with a threshold value; and when the temperature is lower than the threshold value, operating the internal combustion engine (10) in the heating mode.

10. The method according to claim 9, wherein the internal combustion engine (10) further comprises a valve element (40) which is displaceable between a closed position that blocks the conduit element (36) and an open position that releases the conduit element (36) and wherein the valve element (40) is in the open position during the heating mode.

11. The method according to claim 9, wherein the internal combustion engine (10) is in a traction mode during the heating mode.

12. The method according to claim 9, wherein the internal combustion engine (10) further comprises an intercooler (42) disposed in the intake tract (20) downstream of the compressor wheel (28) and wherein air compressed by the compressor wheel (28) is cooled by the intercooler (42).

13. The method according to claim 12, wherein the intercooler (42) is disposed downstream of the second connection point (V2).

14. The method according to claim 9, wherein the intake tract (20) does not have a cooling device for cooling the air in a longitudinal region (L) extending continuously from the compressor wheel (28) to the second connection point (V2).

Description

BRIEF DESCRIPTION OF THE DRAWING

[0021] In the single the FIGURE, the drawing shows a schematic depiction of an internal combustion engine according to the invention for a motor vehicle.

DETAILED DESCRIPTION OF THE DRAWING

[0022] The single the FIGURE shows an internal combustion engine 10 configured as a reciprocating engine of a motor vehicle in a schematic depiction, the motor vehicle preferably being configured as a motor car, in particular as a passenger car, and being able to be driven by means of the internal combustion engine 10, in particular in its traction mode. The motor vehicle has at least one or exactly two axles arranged one after the other in the longitudinal direction of the vehicle, for example. The respective axle has at least or exactly two vehicle wheels spaced apart from each other in the transverse direction, also simply referred to as wheels, for example. At least one of the axles can be driven by means of the internal combustion engine 10 here. By this should particularly be understood that at least the wheels of the at least one axle can be driven by means of the internal combustion engine 10. The vehicle as a whole is driven by driving the wheels. The internal combustion engine 10 has a housing element 12 that is, for example, formed as a ball housing and an output shaft 14 that is, for example, formed as a crankshaft, which can be rotated relative to the housing element 12 around a crankshaft rotation axis. The housing element 12 has several cylinders 16 by which a respective combustion chamber is respectively partially delimited. A piston is received in the respective cylinder 16 in a translationally movable manner, wherein the piston partially delimits the respective combustion chamber. The respective piston is articulatedly connected to the output shaft 14 via a connecting rod, such that translational movements taking place in the respective cylinder 16 and occurring relative to the housing element 12 are transformed into a rotational movement of the output shaft 14. The internal combustion engine 10 is in its fired mode during the previously specified traction mode. In the fired mode, combustion processes occur in the combustion chambers during which a respective mixture of fuel and air is burned in the respective combustion chamber. The pistons are driven by the combustion processes, such that the output shaft 14 is driven by the piston via the connecting rod and is thus rotated around the crankshaft rotation axis relative to the housing element 12. Exhaust gas results from the respective combustion process. The exhaust gas can flow out of the combustion chambers, flow into an exhaust gas tract 18 of the internal combustion engine 10 and flow through the exhaust gas tract 18.

[0023] The respective mixture of fuel and air is also referred to as a mixture, and comprises air and a fuel, in particular a liquid fuel, wherein the respective combustion chamber is provided with the air and with the fuel. In this case, the internal combustion engine 10 has an intake tract 20 that can be flowed through by the air and is also referred to as an inlet tract, by means of which intake tract the air flowing through the intake tract 20 is fed to and particularly into the combustion chambers.

[0024] The internal combustion engine comprises at least one exhaust gas turbocharger 22 here, which has a compressor 24 arranged in the intake tract 20 and a turbine 26 arranged in the exhaust gas tract 18. The compressor 24 has a compressor wheel 28 arranged in the intake tract 20. The turbine 26 comprises a turbine wheel 30 arranged in the exhaust gas tract 18. The compressor 24 additionally comprises a compressor housing 32 depicted only schematically and partially in the FIGURE, in which the compressor wheel 28 is rotatably received. The compressor wheel 28 and the turbine wheel 30 are rotors. The exhaust gas turbocharger 22 also comprises a shaft 34 here. The turbine wheel 30 can be driven by the exhaust gas flowing through the exhaust gas tract 18, and can thus be rotated around a rotor rotation axis relative to the compressor housing 32. The compressor wheel 28 can be driven by the turbine wheel 30 via the shaft 34 here, and thus around the rotor rotation axis relative to the compressor housing 32. The air flowing through the intake tract 20 is thus compressed by means of the compressor wheel 28. Energy contained in the exhaust gas can thus be used to compress the air.

[0025] The internal combustion engine 10 additionally comprises a conduit element 36 which is fluidly connected to the intake tract 20 at a first connection point V1 and at a second connection point V2. The connection point V2 is arranged downstream of the connection point V1 in the flow direction of the air flowing through the intake tract 20, and the connection point V1 is additionally arranged upstream of the compressor wheel 28, while the connection point V2 is arranged downstream of the compressor wheel 28. A method for operating the internal combustion engine 10, particularly in the traction mode, is described in the following with reference to the single the FIGURE

[0026] In order to be able to guarantee a particularly advantageous operation of the internal combustion engine 10, particularly during the traction mode, in a particularly simple manner, the internal combustion engine 10 is operated in a heating mode to heat at least the compressor housing 32, particularly during at least a part of the traction mode, the heating mode thus being carried out simultaneously with the traction mode at least during the specified part, for example. In other words, it is preferably provided that the internal combustion engine 10 is in the traction mode during the heating mode. In the traction mode, at least a part of the air flowing through the intake tract 20 and compressed, and thus warmed, by means of the compressor wheel 28 is removed from the intake tract 20 at the second connection point V2, introduced into the conduit element 36, returned to the first connection point V1 by means of the conduit element 36 and introduced into the intake tract 20 at the first connection point V1. The air can then flow from the connection point V1 back to the connection point V2. The air flows through the compressor housing 32 on its way from the connection point V1 to the connection point V2, such that the compressor housing 32 is heated or kept warm by means of the returned air that has already previously been compressed, and thus heated. The air is additionally compressed again on its way from the connection point V1 and the connection point V2 by means of the compressor wheel 32, and is thus heated further, whereby a particularly high temperature of the air flowing from the connection point V1 to the connection point V2, and flowing through the compressor housing in the process, can thus be obtained. The compressor housing 32 and the component arranged in an environment 38 of the compressor housing 32 can thus be kept warm or heated efficiently and effectively with the internal combustion engine 10.

[0027] The internal combustion engine 10 has a valve element 40 arranged in the conduit element 36 here, the valve element being able to be displaced between a closed position blocking the conduit element 36 and at least one open position releasing the conduit element 36. The valve element 40 is in the open position during the heating mode here. It is preferably provided that the valve element 40 is in the closed position at least during a different part of the traction mode from the heating mode. The valve element 40 is constantly in the closed position during the traction mode, with the exception of the heating mode occurring during the traction mode.

[0028] An intercooler 42 depicted particularly schematically in the FIGURE is arranged in the intake tract 20 downstream of the compressor wheel 28, by means of which intercooler the air compressed by means of the compressor wheel 28 can be cooled. The intercooler 42 is arranged downstream of the connection point V2 here, such that the air is not cooled by means of the intercooler 42 on its way from the connection point V1 to the connection point V2 and from the connection point V2 back to the connection point V1.

[0029] A circulation of the air is depicted in the FIGURE by arrows 44. The circulation takes place during the heating mode here. It can particularly be seen with reference to the arrows 44 that the air circulates via the conduit element 36 and over a longitudinal region L of the intake tract 20 during the heating mode, wherein the longitudinal region L extends exactly from the connection point V1 all the way, and thus without interruption, to exactly the connection point V2, wherein the compressor 24 is arranged in the longitudinal region L. Circulation should particularly be understood to mean that the air flows from the connection point V2 to the connection point V1 via the conduit element 36, and back from the connection point V1 to the connection point V2. A particularly high temperature of the circulating air can be obtained by this circulation, whereby the compressor housing 32 can be heated or can be kept warm effectively and efficiently.

[0030] It can further be seen from the FIGURE that the longitudinal region L of the intake tract 20 extending from the connection point V1 all the way to the connection point V2 does not have a cooling device for cooling the air. It can be seen that the compressor housing 32 and parts bordering or connected to it can be heated and kept warm by the method, particularly during cold ambient conditions, such that an excessive formation of ice can be avoided, particularly upstream of the compressor wheel 28. Damage to the compressor wheel 28 caused by ice can thus be avoided without a separate, additional heating device having to be used.

[0031] The turbine 26 is arranged in a bypass device 46, which has a bypass conduit 48 also referred to as a bypass. The bypass conduit 48 is fluidly connected to the exhaust gas tract 18 at a third connection point V3 and at a fourth connection point V4. The connection point V4 is arranged upstream of the turbine wheel 30 in the flow direction of the exhaust gas flowing through the exhaust gas tract 18, while the connection point V3 is arranged downstream of the turbine wheel 30. At least a part of the exhaust gas flowing through the exhaust gas tract 18 can be removed from the exhaust gas tract 18 at the connection point V4 by means of the bypass conduit 48 and introduced into the bypass conduit 48. The exhaust gas removed at the connection point V4 and introduced into the bypass conduit 48 can flow through the bypass conduit 48 and is guided to the connection point V3 by means of the bypass conduit 48. The exhaust gas flowing through the bypass conduit 48 can be introduced into the exhaust gas tract 18 again at the connection point V3, wherein the exhaust gas flowing through the bypass conduit 48 bypasses the turbine wheel 30, and thus does not drive the turbine wheel 30.

[0032] The bypass device 46 additionally comprises a valve 50, also referred to as a bypass valve, waste gate or waste gate valve, arranged in the bypass conduit 48, by means of which a quantity of the exhaust gas flowing through the bypass conduit 48 can be adjusted, for example. A power of the turbine 26 can be adjusted as needed by adjusting the quantity of the exhaust gas flowing through the bypass conduit 48.

[0033] The internal combustion engine 10 additionally has an exhaust gas recirculation device 52 having an exhaust gas recirculation conduit 54. The exhaust gas recirculation conduit 54 is fluidly connected to the exhaust gas tract 18 at a fifth connection point V5 and fluidly connected to the intake tract 20 at a sixth connection point V6. The connection point V6 is arranged upstream of the compressor wheel 28, and preferably downstream of the connection point V1 in the flow direction of the exhaust gas flowing through the intake tract 20, for example. The connection point V5 is arranged downstream of the turbine wheel 30 in the flow direction of the exhaust gas flowing through the exhaust gas tract 18, for example, wherein the connection point V5 can be arranged upstream or downstream of the connection point V3. At least a part of the exhaust gas flowing through the exhaust gas tract 18 can be removed from the exhaust gas tract 18 at the connection point V5 by means of the exhaust gas recirculation conduit 54 and introduced into the exhaust gas recirculation conduit 54. The exhaust gas removed from the exhaust gas tract 18 at the connection point V5 and introduced into the exhaust gas recirculation conduit 54 can flow through the exhaust gas recirculation conduit 54, and is fed, and thus returned, to the connection point V6 by means of the exhaust gas recirculation conduit 54. The exhaust gas flowing through the exhaust gas recirculation conduit 54 can flow out of the exhaust gas recirculation conduit 54 at the connection point V6, and flow into the intake tract 20. The exhaust gas recirculation device 52 comprises an exhaust gas recirculation valve 56 arranged in the exhaust gas recirculation conduit 54 here, by means of which a quantity of the exhaust gas flowing through the exhaust gas recirculation conduit 54 can be adjusted.

TABLE-US-00001 List of reference characters: 10 internal combustion engine 12 housing element 14 output shaft 16 cylinder 18 exhaust gas tract 20 intake tract 22 exhaust gas turbocharger 24 compressor 26 turbine 28 compressor wheel 30 turbine wheel 32 compressor housing 34 shaft 36 conduit element 38 environment 40 valve element 42 intercooler 44 arrow 46 bypass device 48 bypass conduit 50 bypass valve 52 exhaust gas recirculation device 54 exhaust gas recirculation conduit 56 exhaust gas recirculation valve V1 connection point V2 connection point V3 connection point V4 connection point V5 connection point V6 connection point