DE102019003576A1 - Method for operating an internal combustion engine for a motor vehicle and an internal combustion engine for a motor vehicle - Google Patents

Abstract

The invention relates to a method for operating an internal combustion engine (10) for a motor vehicle, in which a turbine (22) of an exhaust gas turbocharger (20) of the internal combustion engine is driven by an exhaust gas flow (32) generated by the internal combustion engine and guided in an exhaust gas duct (30) of the internal combustion engine. is driven in order to drive a compressor (24) of the exhaust gas turbocharger coupled to the turbine and thereby to supply at least one combustion chamber (12) of the internal combustion engine via an intake duct (40) of the internal combustion engine with a media flow (42) compressed to a predetermined compression state by means of the compressor. In addition to the compressor, an electric machine is also driven by the turbine in order to generate electrical power and at least downstream of the turbine, a low-pressure partial flow (34) of the exhaust gas flow is diverted from the exhaust gas duct and introduced into the intake duct to use the low-pressure partial flow as a To compress the media flow portion of the media flow by the compressor and to feed the media flow to the at least one combustion chamber. Another aspect of the invention relates to an internal combustion engine (10) for a motor vehicle.

Description

The invention relates to a method for operating an internal combustion engine for a motor vehicle, according to the preamble of patent claim 1. Another aspect of the invention relates to an internal combustion engine for a motor vehicle.

To reduce nitrogen oxide emissions, so-called exhaust gas recirculation, or EGR for short, takes place in modern internal combustion engines, in which part of an exhaust gas flow is taken from an exhaust tract of the internal combustion engine, introduced into an intake duct of the internal combustion engine and fed to the respective combustion chambers of the internal combustion engine together with fresh air. Particularly high exhaust gas recirculation rates, or EGR rates for short, can be achieved with what is known as high pressure EGR, in which the part of the exhaust gas flow is taken from the exhaust gas tract upstream of a turbine of an exhaust gas turbocharger and fed to the intake duct. In addition, it is known to use the turbine to drive an electrical generator in order to thereby generate electrical power from mechanical power which is generated by means of the turbine.

For example, the DE 10 2012 004 394 A1 a method in which an electric machine is assigned to an output shaft, another electric machine being assigned to an exhaust gas turbocharger and electrically connected to the first electric machine. The drive device is optionally operated in different operating modes, the internal combustion engine driving the former electrical machine in generator mode through the output shaft and the exhaust gas turbocharger driving the latter electrical machine in its generator mode.

From the DE 10 2016 208 208 A1 an internal combustion engine with a charge air supply and an exhaust gas discharge is known, in which the charge air supply comprises an intake section and an intake pipe section, which are connected to one another via a compressor, the exhaust gas discharge includes a high-pressure section and a low-pressure section, which are connected to one another via a turbine, the exhaust gas discharge via At least one exhaust gas recirculation line is connected to the charge air supply, a first fuel supply being arranged in a first exhaust gas recirculation line, which connects the low-pressure section to the charge air supply, via which fuel can be fed into a first partial exhaust gas flow, which can be supplied to a charge air flow via the first exhaust gas recirculation line.

The object of the present invention is to create a method for operating an internal combustion engine with a particularly high degree of efficiency. Another object of the present invention is to provide an internal combustion engine which can be operated with a particularly high degree of efficiency.

These objects are achieved by a method with the features of patent claim 1 and by an internal combustion engine with the features of patent claim 5. Advantageous refinements with expedient developments of the invention are specified in the remaining claims.

A first aspect of the invention relates to a method for operating an internal combustion engine for a motor vehicle, in which a turbine of an exhaust gas turbocharger of the internal combustion engine is driven by an exhaust gas flow generated by the internal combustion engine and guided in an exhaust gas duct of the internal combustion engine, to a compressor of the exhaust gas turbocharger coupled to the turbine to drive and thereby at least one combustion chamber of the internal combustion engine via an intake duct of the internal combustion engine to supply a media flow compressed to a predetermined compression state by means of the compressor.

According to the invention it is provided that, in addition to the compressor, an electric machine is also driven by the turbine in order to generate electrical power and, at least downstream of the turbine, a low-pressure partial flow of the exhaust gas flow is diverted from the exhaust gas duct and introduced into the intake duct to To compress the low-pressure partial flow as a media flow component of the media flow through the compressor and to feed the media flow to the at least one combustion chamber. The media flow can thus include the low-pressure partial flow so that the media flow can be, for example, an exhaust gas / air mixture. The electrical machine can be assigned to the exhaust gas turbocharger. In other words, the exhaust gas turbocharger can include the electrical machine and can thus be designed as an electrical exhaust gas turbocharger, which can also be abbreviated as eATL.

A significant advantage of the method is that the low-pressure partial flow of the exhaust gas flow is used to drive the turbine and is only then discharged from the exhaust gas duct downstream of the turbine and introduced into the intake duct, whereby the low-pressure partial flow is used as part of the exhaust gas flow can to drive the compressor on the one hand and the electrical machine on the other hand by means of the turbine. Via the compressor driven by the turbine, the media flow can be compressed to the predetermined compression state and, at the same time, electrical power can be generated via the electrical machine driven by the turbine. In other words, using the turbine, at least part of an enthalpy of the low-pressure partial flow can be used to generate the electrical power. Energy contained in the exhaust gas flow and thus also in the low-pressure partial flow can be used to generate the electrical power and thereby make it usable, whereby the internal combustion engine can be operated with a particularly high degree of efficiency. Another advantage is that the exhaust gas flow is expanded and cooled when the turbine is driven, as a result of which the low-pressure partial flow has a lower exhaust gas temperature than would be the case, for example, with high-pressure exhaust gas recirculation. Because of this lower exhaust gas temperature, even a low cooling capacity or a particularly small-sized low-pressure EGR cooler is sufficient to cool the low-pressure partial flow to a predetermined exhaust gas temperature value.

In other words, the output of energy from the low-pressure partial flow to the turbine reduces the cooling capacity for cooling the low-pressure partial flow.

In summary, the turbine of the exhaust gas turbocharger can be operated on the basis of the exhaust gas flow comprising the low-pressure partial flow in such a way that the turbine provides more power than is required by the compressor to compress the media flow to the predetermined compression state, with excess power being output to the electrical machine in order to Generate electrical power and thus operate the internal combustion engine with particularly high efficiency. The electrical power can be supplied to an overall engine system of the internal combustion engine and thus made usable. The electrical power can, for example, be fed to an electric motor connected to a crankshaft of the internal combustion engine, or to another consumer or a battery.

A second aspect of the invention relates to an internal combustion engine for a motor vehicle, with an exhaust gas turbocharger, which comprises a turbine and a compressor coupled to the turbine, with an exhaust gas duct for guiding an exhaust gas flow that can be generated by the internal combustion engine, and with an intake duct via which at least one combustion chamber of the Internal combustion engine can be supplied with a media flow that can be compressed to a predetermined compression state by means of the compressor. According to the invention it is provided that, in addition to the compressor, an electric machine is also coupled to the turbine and can be driven using the turbine in order to generate electrical power, the internal combustion engine having an exhaust gas recirculation line opening into the exhaust gas duct downstream of the turbine, via which the Turbine, a low-pressure partial flow of the exhaust gas flow can be diverted from the exhaust gas duct and, for compressing the low-pressure partial flow as a media flow component of the media flow, can be introduced into the intake duct by means of the compressor in order to supply the media flow to the at least one combustion chamber, the internal combustion engine comprising a control device which is set up for this purpose is to control the exhaust gas turbocharger in such a way that the turbine simultaneously drives the electrical machine and the compressor in order to generate electrical power on the one hand using the electrical machine and on the other hand during operation of the internal combustion engine and the compressor to compress the media flow to the predetermined compression state. The internal combustion engine can be used to carry out a method according to the first aspect of the invention. The internal combustion engine can accordingly be operated with a particularly high degree of efficiency.

The features presented in connection with the method according to the invention according to the first aspect of the invention and their advantages apply accordingly to the internal combustion engine according to the invention according to the second aspect of the invention and vice versa.

Further advantages, features and details of the invention emerge from the following description of preferred exemplary embodiments and on the basis of the drawing (s). The features and combinations of features mentioned above in the description as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures can be used not only in the respectively specified combination, but also in other combinations or alone, without the scope of the Invention to leave.

• 1 eine schematische Darstellung einer Verbrennungskraftmaschine, welche einen elektrischen Abgasturbolader (eATL) umfasst und welche bei Niederdruck-Abgasrückführung sowie bei Hochdruck-Abgasrückführung betrieben werden kann; und
• 2 eine weitere schematische Darstellung der Verbrennungskraftmaschine, deren Betrieb bei Niederdruck-Abgasrückführung durch Abgasentnahme stromab einer Abgasnachbehandlung erfolgt.

Show:

• 1 a schematic representation of an internal combustion engine which comprises an electric exhaust gas turbocharger (eATL) and which can be operated with low pressure exhaust gas recirculation and with high pressure exhaust gas recirculation; and
• 2 Another schematic representation of the internal combustion engine, the operation of which takes place with low-pressure exhaust gas recirculation through exhaust gas extraction downstream of an exhaust gas treatment.

Identical and functionally identical elements are provided with the same reference symbols in the figures.

1 and 2 each show a schematic representation of an internal combustion engine 10 for a motor vehicle not shown further here.

The internal combustion engine 10 comprises a plurality of cylinders with respective combustion chambers 12 as well as an intake duct 40 over which the cylinders or the combustion chambers 12 a media stream 42 in the form of an air / exhaust gas mixture for low-nitrogen oxide combustion in the combustion chambers 12 injected fuel can be supplied. Via an exhaust duct 30th the internal combustion engine 10 an exhaust gas flow resulting from the combustion of the fuel 32 from the combustion chambers 12 be diverted. The exhaust duct 30th is therefore used to guide the internal combustion engine 10 generated exhaust gas flow 32 . The internal combustion engine 10 also includes a control device 14th , which is designed as an engine control unit.

It also includes the internal combustion engine 10 an exhaust gas turbocharger 20th , which one with the exhaust duct 30th coupled turbine 22nd and one with the turbine 22nd coupled compressor 24 includes. The exhaust gas flow 32 points upstream of the turbine 22nd , i.e. before entering the turbine 22nd an exhaust temperature T3 which is greater than a further exhaust gas temperature T4 downstream of the turbine 22nd , i.e. after the exhaust gas flow leaves 32 from the turbine 22nd . The exhaust gas temperatures T3 , T4 are also in 1 and in 2 shown.

The turbine 22nd can be designed as a mono-scroll turbine, as a twin-scroll turbine, as a single-stage segment turbine, as a multi-stage segment turbine or as a turbine with variable turbine geometry in order to enable the most needs-based use of exhaust gas energy.

The turbine 22nd is when the internal combustion engine is operating 10 through the exhaust gas flow 32 driven. The compressor 24 is in turn by the turbine 22nd powered. The compressor 24 compresses the media stream 42 to a predetermined compression state and promotes the media flow 42 via the intake duct 40 towards the respective combustion chambers 12 . Before the entry of the media flow 42 into the respective combustion chambers 12 becomes the media flow 42 using one in the intake duct 40 integrated charge air cooler 66 cooled so that the media flow 42 before entering the respective combustion chambers 12 one in 1 and in 2 shown air inlet temperature T2S having.

In addition to the compressor 24 is also an electrical machine in the present case 26th with the turbine 22nd coupled. The electric machine 26th can in the exhaust gas turbocharger 20th be integrated so that the exhaust gas turbocharger 20th can be designed as a so-called electric exhaust gas turbocharger, eATL for short. The electric machine 26th is in the present case designed as a motor generator and can accordingly - depending on requirements - be operated as a motor and a generator. When operated as a motor, the electrical machine 26th the compressor 24 drive, for example to avoid or at least reduce so-called "turbo holes". When operated as a generator, the electric machine 26th through the turbine 22nd be driven around using the electric machine 26th electrical power P _el to generate.

The internal combustion engine 10 has a downstream of the turbine for low-pressure exhaust gas recirculation 22nd in the exhaust duct 30th opening exhaust gas recirculation line 33 on what is downstream of the turbine 22nd a low pressure partial flow 34 of the exhaust gas flow 32 from the exhaust duct 30th diverted and for compressing the low-pressure partial flow 34 by means of the compressor 24 as media flow component of the media flow 42 in the intake duct 40 is introduced to the compressed media flow 42 the combustion chambers 12 feed. Downstream a coupling point at which the exhaust gas recirculation line 33 in the exhaust duct 30th opens, the exhaust gas flow 32 (from which previously the low-pressure partial flow 34 via the exhaust gas recirculation line 33 was removed) an exhaust gas temperature T5 which is lower than the exhaust gas temperatures T3 , T4 is. The exhaust temperature T5 is present only in 1 shown.

The control device 14th is set up to do this, the exhaust gas turbocharger 20th to be controlled in such a way that the turbine 22nd at the same time the electric machine 26th and the compressor 24 drives to the operation of the internal combustion engine 10 on the one hand using the electric machine 26th to generate electrical power and on the other hand using the compressor 24 the media flow 42 to compress to the predetermined compression state. Using the control device 14th can the electric machine 26th can also be controlled in such a way that the electrical machine 26th if necessary as an electric motor works to the compressor 24 to drive.

In the exhaust gas recirculation line 33 is also a particle filter 60 integrated so that the low pressure partial flow 34 after being discharged from the exhaust duct 30th through the particle filter 60 cleaned, then through an exhaust gas cooler 62 cooled and then into the intake duct 40 is initiated. The exhaust gas cooler 62 is accordingly designed as a low-pressure EGR cooler in the present case. The cooling of the low-pressure partial flow 34 by means of the exhaust gas cooler 62 contributes to an increase in efficiency and a reduction in nitrogen oxide emissions. Through the particle filter 60 can cause sooting of the exhaust gas cooler 62 , i.e. contamination of the exhaust gas cooler 62 with particles, at least be delayed.

As in 1 and 2 can be seen, the internal combustion engine 10 also an additional exhaust gas recirculation line 35 on what upstream of the turbine 22nd a high pressure partial flow 36 of the exhaust gas flow 30th from the exhaust duct 30th diverted and into the intake duct 40 is initiated. In the additional exhaust gas recirculation line 35 can, for example, be a valve designed as a 2/2-way valve 72 be integrated. The internal combustion engine 10 can therefore be operated particularly flexibly both with low-pressure exhaust gas recirculation and with high-pressure exhaust gas recirculation, whereby nitrogen oxide emissions can be effectively and flexibly reduced.

The high pressure partial flow 36 becomes after being discharged from the exhaust duct 30th through an additional exhaust gas cooler 64 cooled and then into the intake duct 40 initiated. The additional exhaust gas cooler 64 is in the present case accordingly designed as a high-pressure EGR cooler. The cooling of the high-pressure partial flow 36 through the additional exhaust gas cooler 64 carries - just like the cooling of the low-pressure partial flow 34 by means of the exhaust gas cooler 62 - to increase efficiency and to reduce nitrogen oxide emissions.

While in 1 only the particle filter 60 for exhaust gas aftertreatment in the exhaust gas recirculation line 33 is integrated and the low-pressure exhaust gas recirculation takes place close to the engine, is the exhaust gas cooler 62 in 2 an exhaust aftertreatment system 61 upstream, which is the particle filter 60 may include. The exhaust aftertreatment system 61 can comprise one or more catalytic converters, for example an oxidation catalytic converter and additionally or alternatively a nitrogen oxide storage catalytic converter.

When operating the internal combustion engine 10 the low-pressure exhaust gas recirculation and additionally or alternatively the high-pressure exhaust gas recirculation can take place as required. In other words, the internal combustion engine can 10 that is, with a multi-way EGR (multi-way exhaust gas recirculation, in which the high pressure exhaust gas recirculation and the low pressure exhaust gas recirculation can be used alternately or simultaneously). Thus, the low-pressure partial flow 34 after (downstream) the turbine 22nd of the exhaust gas turbocharger 20th and additionally or alternatively the high-pressure partial flow 36 in front of (upstream) the turbine 22nd can be removed.

The turbine 22nd can deliberately be designed to be small, with the crankshaft of the internal combustion engine at higher speeds 10 and a correspondingly large volume flow of the exhaust gas flow 32 diverting a partial exhaust gas flow of the exhaust gas flow 32 via a bypass 75 and thus past the turbine 22nd can be done.

In the bypass 75 can be a valve 74 be integrated, which can be designed as a so-called wastegate valve and by means of the control device 14th can be controlled. By controlling the valve 74 Accordingly, a boost pressure control can take place in order to avoid that the turbine 22nd too large a volume flow is applied.

Through the use of the deliberately small turbine 22nd can in particular in partial load operation of the internal combustion engine 10 the low pressure partial flow 34 as part of the exhaust gas flow 32 can be used to make an additional contribution to the turbine output, i.e. through the turbine 22nd mechanical power that can be generated. Thanks to the clever design of the turbine 22nd and compressor 24 this contribution is higher than for the subsequent compression of the low-pressure partial flow 34 (then as part of the media flow 42 ) required compression power, so that in total an advantage is achieved through which the efficiency of the exhaust gas turbocharger 20th and thus the entire internal combustion engine 10 can be significantly improved. Especially with large volume flows of the low-pressure partial flow 34 and accordingly large EGR rates can produce a lot of electrical power P _el based on the electrical machine 26th and a correspondingly large improvement in efficiency can be achieved, especially in part-load operation, especially since higher EGR rates are generally used in part-load operation than in full-load operation.

In the exhaust gas recirculation line 33 can, for example, be a valve designed as a 2/2-way valve 76 be integrated, which either - as in 1 and 2 shown - upstream of the exhaust gas cooler 62 arranged or downstream of the exhaust gas cooler 62 can be arranged. Additionally or alternatively, an in 1 and 2 shown and designed as a 3/2-way valve 78 in the exhaust duct 30th and thus be arranged in the main stream. That for the low-pressure exhaust gas recirculation in the form of the low-pressure partial flow 34 The extracted exhaust gas can either be located close to the engine after the exhaust gas turbocharger 20th from the exhaust duct 30th as in 1 is shown, or alternatively - as in 2 is shown - after or from the exhaust aftertreatment system 61 , which can be designed as an exhaust aftertreatment box. With extraction close to the engine - there is an entry of soot particles and other harmful components into the intake duct 40 , which can also be referred to as the air intake section, to be prevented - in the exhaust gas recirculation line 33 optional the particle filter 60 integrated. In this case the 2/2-way valve (valve 76 ) to control the low-pressure partial flow 34 (EGR mass flow) ideally before and thus upstream of the particle filter 60 attached to when the particulate filter needs to be regenerated 60 to be able to achieve higher temperatures (function like brake flap). If necessary, the necessary pressure gradient for an EGR rate transport can be increased with a flap after the extraction point. This flap is also known as the so-called "brake flap" and can be used to increase the temperature of the exhaust gas (exhaust gas flow 32 ) can be used. The advantage of the arrangement close to the engine is that there is already a certain pressure gradient for exhaust gas transport of the low-pressure partial flow 34 through the (in 1 exhaust aftertreatment box (not shown) (exhaust aftertreatment system 61 ) given is. Additionally or alternatively, the low-pressure partial flow 34 after the exhaust aftertreatment system 61 or according to subcomponents of the exhaust aftertreatment system 61 can be removed. To ensure the transport of the low-pressure partial flow 34 can in this case a valve designed as a flap 78 downstream of an extraction point for the low-pressure partial flow 34 to the exhaust duct 30th be arranged. Optionally, the turbine 22nd the valve 74 (as a wastegate valve, also called bypass valve). This allows system properties to be changed with regard to dynamic requirements or for temperature control and power control.

Via the bypass 75 is bypassing the exhaust gas turbocharger 20th , so an at least partial diversion of the exhaust gas flow 32 bypassing the turbine 22nd , especially when starting the internal combustion engine from cold 10 possible, which means that the exhaust gas aftertreatment system is heated up more quickly 61 or individual components of the exhaust aftertreatment system 61 is made possible. In this case the compressor can 24 by operating the electrical machine 26th be driven as an electric motor. The electric machine 26th can be used to drive the compressor 24 for example, be supplied with energy via a battery not shown here.

In summary, the present method makes the electric exhaust gas turbocharger 20th operated at low pressure exhaust gas recirculation, the low pressure partial flow 34 by removing it downstream of the turbine 22nd from the exhaust duct 30th an additive contribution to the turbine 22nd output power of the exhaust gas turbocharger 20th (eATL) delivers. Thanks to the optimized design of the turbine 22nd it delivers more power than the compressor 24 needed. This additional power is sent to the electrical machine 26th output when the latter is operated as a generator. The higher the volume flow of the low-pressure partial flow 34 is, the higher the additional output, both to the compressor 24 , as well as to the electrical machine 26th . Due to the increased power output to the electrical machine 26th a considerable increase in efficiency can be achieved.

The relationships described below are used to determine the electrical power P _el which can be achieved by the process with low-pressure exhaust gas recirculation.

$$\mathrm{\Delta }{\dot{H}}_T={\eta }_{ATL}\ast {\dot{m}}_A\ast c_p\ast \left(T_3-T_4\right)=P_{Verdichter}$$

mit

• ṁ_A = Abgasmassenstrom des Abgasstroms 32 abzüglich des Hochdruck-Teilstroms 36;
• c_p = spezifische Wärmekapazität;
• η_ATL = Wirkungsgrad des ATL; und
• P_Verdichter = Leistung des Verdichters 24.

For an enthalpy flow difference ΔḢ _T at the turbine, the following applies for high-pressure exhaust gas recirculation without taking friction losses into account and when using a conventional standard turbine: $$\mathrm{\Delta }{\dot{H}}_T={\dot{m}}_{\mathrm{A.}}\ast c_p\ast \left(T_3-T_{\mathrm{4th}}\right)=P_{VerdicHter}$$

$$\mathrm{\Delta }{\dot{H}}_T={\eta }_{\mathrm{A.}T\mathrm{L.}}\ast {\dot{m}}_{\mathrm{A.}}\ast c_p\ast \left(T_3-T_{\mathrm{4th}}\right)=P_{VerdicHter}$$

With

• ṁ _A = exhaust gas mass flow of the exhaust gas flow 32 minus the high-pressure partial flow 36 ;
• c _p = specific heat capacity;
• η _ATL = efficiency of the ATL; and
• P _compressor = capacity of the compressor 24 .

mit
$T_3^{*}$

= Abgastemperatur vor der Turbine 22.By using the smaller turbine compared to the standard turbine 22nd (causing the turbine 22nd delivers more power than the compressor 24 required) results in: $$\begin{array}{l}\mathrm{\Delta }{\dot{H}}_T={\eta }_{\mathrm{A.}T\mathrm{L.}}\ast {\dot{m}}_{\mathrm{A.}}\ast c_p\ast \left(T_3^{*}-T_{\mathrm{4th}}\right)={\eta }_{\mathrm{A.}T\mathrm{L.}}\ast {\dot{m}}_{\mathrm{A.}}\ast c_p\ast \left[\left(T_3^{*}-T_3\right)+\left(T_3-T_{\mathrm{4th}}\right)\right]\\ =P_{el}+P_{VerdicHter}\end{array}$$

With
$T_3^{*}$

= Exhaust gas temperature upstream of the turbine 22nd .

Mit η_Turbine = Wirkungsgrad der TurbineThe electrical power is thus calculated P _el during operation with high pressure exhaust gas recirculation $$P_{el}={\eta }_{Turbine}\ast {\dot{m}}_{\mathrm{A.}}\ast c_p\ast \left(T_3^{*}-T_3\right)$$

With η _turbine = efficiency of the turbine

mit
ṁ_AGR = Massenstrom des Niederdruck-Teilstroms 34.The additional electrical power P _el when operating with low-pressure exhaust gas recirculation, however, results in $$P_{el}={\eta }_{Turbine}\ast \left({\dot{m}}_{\mathrm{A.}}+{\dot{m}}_{\mathrm{A.}G\mathrm{R.}}\right)\ast c_P\ast \left(T_3^{*}-T_3\right)$$

With
ṁ _EGR = mass flow of the low-pressure partial flow 34 .

The electrical power output P _el increases - assuming the same turbocharger efficiencies - when operating with low-pressure exhaust gas recirculation by a proportion that is the low-pressure partial flow 34 delivers with the same gas exchange loss.

List of reference symbols

10

Internal combustion engine

12

Combustion chamber

14th

Control device

20th

Exhaust gas turbocharger

22nd

turbine

24

compressor

26th

electric machine

30th

Exhaust duct

32

Exhaust gas flow

33

Exhaust gas recirculation line

34

Low pressure partial flow

35

Additional exhaust gas recirculation line

36

High pressure partial flow

40

Intake duct

42

Media flow

60

Particle filter

61

Exhaust aftertreatment system

62

Exhaust gas cooler

64

Additional exhaust gas cooler

66

Intercooler

72

Valve

74

Valve

75

bypass

76

Valve

78

Electric power valve

P _el

electrical power

T2S

Inlet temperature

T3

Exhaust gas temperature

T4

Exhaust gas temperature

T5

Exhaust gas temperature

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• DE 102012004394 A1 [0003]
• DE 102016208208 A1 [0004]

Claims (6)

A method for operating an internal combustion engine (10) for a motor vehicle, in which a turbine (22) of an exhaust gas turbocharger (20) of the internal combustion engine (10) through one generated by the internal combustion engine (10) and in an exhaust gas duct (30) of the internal combustion engine (10) guided exhaust gas flow (32) is driven in order to drive a compressor (24) of the exhaust gas turbocharger (20) coupled to the turbine (22) and thereby at least one combustion chamber (12) of the internal combustion engine (10) via an intake duct (40) of the internal combustion engine (10) ) to supply a media stream (42) compressed to a predetermined compression state by means of the compressor (24), characterized in that, in addition to the compressor (24), an electrical machine (26) is also driven by the turbine (22) in order to supply electrical power generate and at least downstream of the turbine (22) a low-pressure partial flow (34) of the exhaust gas flow (32) from the exhaust gas duct (30) is diverted and introduced into the intake duct (40) in order to compress the low-pressure partial flow (34) as a media flow component of the media flow (42) by the compressor (24) and to feed the media flow (42) to the at least one combustion chamber (12). Procedure according to Claim 1 , characterized in that the low-pressure partial flow (34) is cleaned by a particle filter (60) after being discharged from the exhaust gas duct (30), then cooled by an exhaust gas cooler (62) and then introduced into the intake duct (40). Procedure according to Claim 1 or 2 , characterized in that upstream of the turbine (22) a high-pressure partial flow (36) of the exhaust gas flow (30) is discharged from the exhaust gas duct (30) and introduced into the intake duct (40). Procedure according to Claim 3 , characterized in that the high-pressure partial flow (36) after being discharged from the exhaust gas duct (30) is cooled by an additional exhaust gas cooler (64) and then introduced into the intake duct (40). Internal combustion engine (10) for a motor vehicle, with an exhaust gas turbocharger (20) which comprises a turbine (22) and a compressor (24) coupled to the turbine (22), with an exhaust gas duct (30) for guiding one of the internal combustion engine (10) ) exhaust gas flow (32) that can be generated and with an intake duct (40), via which at least one combustion chamber (12) of the internal combustion engine (10) a media flow (42) which can be compressed to a predetermined compression state by means of the compressor (24) can be fed, characterized in that In addition to the compressor (24), an electric machine (26) is also coupled to the turbine (22) and can be driven by means of the turbine (22) in order to generate electrical power, the internal combustion engine (10) having a downstream of the turbine (22) has exhaust gas recirculation line (33) which opens into the exhaust gas duct (30) and via which a low-pressure partial flow (34) of the exhaust gas flow (32) discharges from the exhaust gas duct (30) downstream of the turbine (22) tbar and for compressing the low-pressure partial flow (34) can be introduced into the intake duct (40) as a media flow component of the media flow (42) by means of the compressor (24) in order to feed the media flow (42) to the at least one combustion chamber (12), the Internal combustion engine (10) comprises a control device (14) which is set up to control the exhaust gas turbocharger (20) in such a way that the turbine (22) simultaneously drives the electrical machine (26) and the compressor (24) to enable the internal combustion engine ( 10) on the one hand to generate electrical power using the electric machine (26) and on the other hand to compress the media flow (42) to the predetermined compression state using the compressor (24). Internal combustion engine (10) after Claim 5 , characterized in that the turbine (22) is designed as a mono-scroll turbine, as a twin-scroll turbine, as a single-stage segment turbine, as a multi-stage segment turbine or as a turbine with variable turbine geometry.

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