DE102017105612A1 - Drive system and motor vehicle - Google Patents

Abstract

A drive system for a motor vehicle comprises an internal combustion engine, which comprises an internal combustion engine 10 and an exhaust line, via which exhaust gas can be discharged from the internal combustion engine 10, and a (steam) cycle process device, wherein the cycle device comprises a circulation system for a fluid into which
an evaporator 16 integrated in the exhaust tract of the internal combustion engine for evaporating the fluid,
an expansion device 12 for expanding the fluid,
a condenser 22 for condensing the fluid and
- A pump 14 for conveying the fluid are integrated in the circulatory system, wherein the evaporator 16 and the expansion device 12 are spaced from each other integrated into the drive system and connected to each other by means of a fluid line 28. According to the invention, such a drive system is characterized in that the fluid line 28 is guided at least partially within an exhaust pipe 30 of the exhaust gas line. Thereby, a loss of heat energy of the guided through the fluid line 28 fluid and thus a loss of efficiency for the feasible by means of the cycle processing device cycle can be kept low.

Description

The invention relates to a drive system for a motor vehicle and a motor vehicle with such a drive system.

Motor vehicles are currently mostly driven by internal combustion engines in which burned fuels and the heat energy released thereby is partially converted into mechanical work. The efficiency of reciprocating internal combustion engines, which are used almost exclusively for driving motor vehicles, is about one third of the primary energy used. Accordingly, represent two-thirds of the heat energy released during combustion waste heat, which is discharged either via the engine cooling or the exhaust system as heat loss to the environment. Utilization of this waste heat is one way to increase the overall efficiency of a drive system of a motor vehicle and thus reduce fuel consumption.

The DE 10 2009 028 467 A1 describes a device for using waste heat of an internal combustion engine. For this purpose, in the exhaust system of the internal combustion engine, a first heat exchanger, the evaporator, a (steam) integrated circuit process device. The heat energy transferred from the exhaust gas to a working medium of the cycle device in the heat exchanger is partially converted into mechanical energy in an expansion device, which can be used, for example, to assist the propulsion of a motor vehicle or to generate electrical energy. Downstream of the expansion device, the working medium is cooled in a second heat exchanger, the condenser, where it condenses. About a pump, an increase in pressure of the working fluid and its supply to the evaporator.

The WO 2012/025776 A1 discloses a drive system for a motor vehicle having an internal combustion engine, an exhaust line for the internal combustion engine, in which an exhaust aftertreatment device is integrated, and with a cycle device, which is provided for the utilization of waste heat of the internal combustion engine for generating mechanical power by means of an expansion device. The exhaust aftertreatment device, which may be formed in particular as an SCR catalyst, is associated with a metering device, through which upstream of the exhaust aftertreatment device, an exhaust aftertreatment agent can be metered into the exhaust gas. The exhaust gas aftertreatment agent used is the same fluid that serves as the working medium in the cycle device.

The DE 695 24 414 T2 describes a system for recovering heat from the exhaust gas of an internal combustion engine of a motor vehicle, in which the branched off from the exhaust gas by means of a heat exchanger heat energy is transmitted to the cooling system of the motor vehicle, after a cold start of the internal combustion engine, a faster reaching an operating temperature range and in particular a faster effect to allow an interior heating of the motor vehicle.

A cycle device which is used for the use of waste heat of an internal combustion engine of a motor vehicle, is further from the respective DE 10 2012 113 092 A1 , of the DE 60 2005 001 788 A1 and the DE 10 2016 100 298 A1 known.

It was an object of the invention to maximize the efficiency of a cycle process that can be carried out by means of a cycle process device integrated into a drive system for a motor vehicle.

This object is achieved by means of a drive system according to the patent claim 1. A motor vehicle with such a drive system is the subject of claim 6. Advantageous embodiments of the drive system according to the invention and thus of the motor vehicle according to the invention are objects of the other claims and / or emerge from the following description of the invention.

The invention is based on the finding that the efficiency of a cycle process that can be carried out by means of a cycle process device, in particular the Rankine process, can be improved, inter alia. from the heat energy that the fluid or working medium has on entering the expansion device, wherein for maximization of the efficiency losses of the heat energy transferred to the fluid in the evaporator of the cycle device should be minimized until the fluid reaches the expansion device Has. Such heat losses can occur to a relevant degree, in particular, if, as is often the case with the integration of a cycle device in a motor vehicle due to insufficient available space, the evaporator on the one hand and the expansion device on the other hand are arranged at a relatively large distance from each other , This distance must then be bridged by means of a correspondingly long, connecting these components fluid line, wherein in the flow through this fluid line heat energy of the fluid is transmitted via the wall of the fluid line to the environment.

In order to minimize the heat losses of the fluid when flowing through the fluid line connecting the evaporator to the expansion device, it may be provided to thermally insulate them, for example by carrying out them as double-walled or surrounded on the outside by an insulating layer. However, this represents a not inconsiderable additional design effort by which the production costs for a cycle device are increased to a relevant extent.

The often directly integrated into an exhaust pipe of an exhaust system of the motor vehicle evaporator is regularly positioned relatively close to the engine of the motor vehicle located in the exhaust line to achieve its application with the hotest possible exhaust gas, which is beneficial to the height of the fluid therein Circular process device affects transmittable heat energy. On the other hand, for the expansion device of the cycle device, for example, for reasons of limited space available and / or for reasons of uniform weight distribution over the axles of the motor vehicle, especially an arrangement in the region of the rear of the motor vehicle could be advantageous. However, since the exhaust gas system of a motor vehicle usually also extends from an internal combustion engine integrated into the front of the motor vehicle to an exhaust gas outlet located at the rear, it is advantageously possible to connect the fluid line with the evaporator integrated in the exhaust gas line Expansion device is provided to allow to run in at least a portion within the exhaust pipe, whereby losses of heat energy flowing through the fluid conduit fluid can be kept low without elaborate isolation measures for the fluid line. This is due to the fact that the temperature of the exhaust gas is regularly significantly higher than the ambient temperature, so that by a correspondingly smaller difference to the temperature of the fluid flowing through the fluid conduit, the heat transfer via the wall of the fluid line is reduced accordingly. On the other hand, the fluid line is exposed by their arrangement within the exhaust pipe not that ambient air flow resulting from the driving operation of the motor vehicle and at a not shielded against the ambient air flow integration of the fluid line into the motor vehicle as a result of forced convection also to a considerable extent to a heat loss of the fluid line would carry fluids flowing through. By the arrangement of the fluid line within the exhaust pipe, however, this is only exposed to the exhaust gas flow, the flow velocity is, however, regularly from relatively low speeds of the motor vehicle is less than the flow velocity of the ambient air flow. Overall, as a result of the at least one section provided arrangement of the fluid line within the exhaust pipe compared to a conventional arrangement outside of the exhaust pipe and in particular in the region of the underbody of a motor vehicle, a significant reduction in heat losses for the fluid flowing through the fluid line can be achieved.

• - ein in den Abgasstrang der Brennkraftmaschine integrierter Verdampfer zum Verdampfen des Fluids,
• - eine Expansionsvorrichtung zum Expandieren des Fluids, beispielsweise ein Axialkolbenmotor oder eine Turbine,
• - ein Kondensator zum Kondensieren des Fluids und
• - eine Pumpe zum Fördern (und vorzugsweise auch zur Druckerhöhung) des Fluids in dem Kreislaufsystem

integriert sind, wobei der Verdampfer und die Expansionsvorrichtung beabstandet voneinander in das Antriebssystem integriert und mittels einer Fluidleitung miteinander verbunden sind. Erfindungsgemäß gekennzeichnet ist ein solches Antriebssystem dadurch, dass die Fluidleitung zumindest teilweise (insbesondere für eine Länge von mindestens 20 cm, 30 cm oder 50 cm) innerhalb eines Abgasrohrs des Abgasstrangs geführt ist.According to these findings, a drive system for a motor vehicle is provided according to the invention, which comprises an internal combustion engine, which is an internal combustion engine and an exhaust line, via the exhaust gas from the internal combustion engine can be discharged comprises, and a (steam) cycle process device, wherein the cycle device a circulation system for a Fluid (working medium) has, in the

• an evaporator integrated in the exhaust gas line of the internal combustion engine for evaporating the fluid,
• an expansion device for expanding the fluid, for example an axial-piston engine or a turbine,
• a condenser for condensing the fluid and
• - A pump for conveying (and preferably also for increasing the pressure) of the fluid in the circulatory system

integrated, wherein the evaporator and the expansion device spaced apart from each other in the drive system integrated and connected to each other by means of a fluid line. According to the invention, such a drive system is characterized in that the fluid line is guided at least partially (in particular for a length of at least 20 cm, 30 cm or 50 cm) within an exhaust pipe of the exhaust gas line.

In principle, it is possible to arrange individual or all further fluid lines of the circulatory system, in particular the fluid line connecting the pump to the evaporator, also (or even exclusively) within an exhaust pipe of the exhaust line to minimize losses of heat energy of the already relatively high temperature fluid to hold or even to realize a preheating of the fluid before reaching the evaporator. However, the inventively provided arrangement of the evaporator with the expansion device connecting fluid line within the exhaust pipe is particularly advantageous because in this section of the circulation system, the fluid in the vaporized and in particular also overheated state and thus, based on the means of the cycle device feasible cycle process, with the highest possible temperature, so that then achievable by this arrangement according to the invention, advantageous effect is also maximized.

Since the arrangement of a fluid line within an exhaust pipe can also bring disadvantages, for example an increased flow resistance for the exhaust gas flowing through the exhaust pipe and / or the need for a different and especially larger dimensions of the exhaust pipe, it may be advantageous according to the invention, only with the evaporator to arrange the expansion device connecting fluid line (at least in a section) within the exhaust pipe, while the remaining fluid lines of the circulation system of the cycle device are arranged outside of the exhaust pipe.

As already described, it may i.a. be advantageous for reasons of the available space, the expansion device in comparison to the evaporator further towards the rear of a drive system according to the invention comprehensive (inventive) motor vehicle to arrange so that may preferably be provided that the fluid line, starting from the evaporator, within the Exhaust pipe is guided in the direction of an exhaust gas outlet of the exhaust line.

Furthermore, it may be appropriate that the evaporator downstream (with respect to a proposed flow direction of the exhaust gas in the exhaust line) of an exhaust aftertreatment device, with several exhaust aftertreatment devices preferably downstream of all exhaust aftertreatment devices or at least downstream of those exhaust aftertreatment devices that require a relatively high operating temperature for their effectiveness and therefore on accordingly high exhaust gas temperatures are dependent, is integrated into the exhaust system. As a result, deteriorated exhaust gas values due to a cooling of the exhaust gas which has a negative effect on the effectiveness of at least one exhaust gas aftertreatment device can be avoided by a transition of heat energy to the fluid of the cycle device in the evaporator.

It is preferably provided that the fluid line of the circulatory system connecting the evaporator to the expansion device is arranged as far as possible within the exhaust pipe and this also applies, in particular, to an outlet of the evaporator to which the fluid line is connected. As a result, the advantageous effect of the arrangement of the fluid line according to the invention within the exhaust gas flow can be maximized. However, this can in particular in a preferably provided embodiment of the drive system according to the invention, wherein the evaporator to achieve the highest possible heat transfer from the exhaust gas to the fluid as a countercurrent heat exchanger (ie as a heat exchanger by the exhaust on the one hand and the fluid on the other hand at least partially in If the fluid outlet of the evaporator provided for the connection of the fluid line can then be arranged at the end of the evaporator located upstream with respect to the direction of flow of the exhaust gas, while the fluid line can preferably be provided starting from the evaporator in the direction of the exhaust gas outlet of the exhaust line and thus extends downstream of the compressor. This may thus result in leading the fluid line in a connected to the fluid outlet of the evaporator first portion parallel to the evaporator within the exhaust line or even within the evaporator itself, resulting in a return of the evaporator previously flowing in the opposite direction fluid in or with respect to the Evaporator corresponds. However, since this can be associated with an increased design effort, it can also be provided to arrange this parallel to the evaporator section of the fluid line and possibly even the fluid outlet of the evaporator outside the exhaust line and the fluid line only downstream (with respect to the flow direction of the exhaust gas) of the evaporator to transfer into the exhaust pipe to let it run from there inside the exhaust pipe. This can in particular make it possible to resort to conventional, freely available evaporators in order to form a drive system according to the invention.

The cycle device of a drive system according to the invention may further comprise an electric machine mechanically connected to the expansion device to convert a mechanical power generated by the expansion device due to the expansion of the fluid into electrical power.

The invention also relates to a motor vehicle comprising a drive system according to the invention, wherein the internal combustion engine of the drive system can be provided in particular for generating a drive power for the motor vehicle. The motor vehicle may in particular be a wheel-based motor vehicle (preferably a car or a truck). Use in other motor vehicles, such as rail vehicles or ships, is also possible.

• 1: in schematischer Darstellung ein erfindungsgemäßes Antriebssystem gemäß einer ersten Ausgestaltungsform;
• 2: in schematischer Darstellung ein erfindungsgemäßes Antriebssystem gemäß einer zweiten Ausgestaltungsform;
• 3: ein zu einem mittels einer Kreisprozessvorrichtung durchführbaren Clausius-Rankine-Prozess gehöriges T-S-Diagramm;
• 4: in einem Diagramm die Änderung des Wärmeübergangskoeffizienten sowie der Geschwindigkeit, mit der eine Fluidleitung einer Kreisprozessvorrichtung eines Antriebssystems durch entweder Umgebungsluft oder Abgas umströmt wird, in Abhängigkeit von der Fahrgeschwindigkeit des Kraftfahrzeugs; und
• 5: ein erfindungsgemäßes Kraftfahrzeug.

The invention will be explained in more detail below with reference to exemplary embodiments illustrated in the drawings. In the drawings shows:

• 1 in a schematic representation of an inventive drive system according to a first embodiment;
• 2 in a schematic representation of an inventive drive system according to a second embodiment;
• 3 a TS diagram associated with a Clausius Rankine process that can be performed by means of a cycle device;
• 4 in a diagram, the change in the heat transfer coefficient and the speed at which a fluid line of a cycle device of a drive system is surrounded by either ambient air or exhaust gas, depending on the driving speed of the motor vehicle; and
• 5 : a motor vehicle according to the invention.

The 1 and 2 show two embodiments of inventive drive systems, each having an internal combustion engine with an internal combustion engine 10 and a cycle device.

During operation of the respective cycle device, a vaporized and superheated as well as pressurized fluid expands in an expansion device 12 whereby a part of the thermal and potential energy of the fluid is converted into mechanical energy. The fluid is for this purpose in the liquid state by means of a pump 14 the cycle processor to an evaporator 16 promoted, in which this is heated by a transition of heat energy. The in the evaporator 16 Heat energy used to heat the fluid comes from exhaust gas produced by the combustion of a fuel-fresh gas mixture in combustion chambers 18 of the internal combustion engine 20 generated and discharged via an exhaust line of the internal combustion engine, wherein the evaporator 16 is integrated into the exhaust line such that this permanently or as needed (in an optional, not shown integration of the evaporator 16 bypass gas bypass) is traversed by the exhaust gas or can be. Before reaching the evaporator 16 The exhaust gas first flows through an exhaust aftertreatment device 20, for example a catalyst. After flowing through the evaporator 16 is the exhaust gas to a particular at a rear of a motor vehicle (see. 5 ) located exhaust outlet 40 guided.

That in the evaporator 16 vaporized and superheated fluid flows to the expansion device designed, for example, as an axial piston motor 12 and from this in a relaxed (re) n state to a capacitor 22 the cycle processor. In the condenser 22, the fluid is heated by a heat transfer to a cooling medium, for example to a coolant, which is also in an internal combustion engine 10 integrating cooling system flows, cooled. In this case, the fluid condenses, so that it in the liquid state by means of the pump 14 via a surge tank 24 can be fed again to the evaporator 16. Due to the promotion of the liquid fluid by means of the pump 14 will also be a compression of the between the evaporator 16 and the expansion device 12 achieved in the gaseous state fluid to a designated operating pressure, wherein the pressure generation by means of the pump 14 interacts with the expansion of the gaseous fluid in the expansion device 12.

The by means of the expansion device 12 mechanical power generated by the expansion of the gaseous fluid may be, for example, the generation of electrical power by means of an output shaft of the expansion device 12 mechanically connected and regeneratively operated electric machine 26 serve, the electrical energy thus generated, for example, in a battery (not shown) can be stored. This electrical energy is then available for various functions of a motor vehicle according to the invention comprising the drive system (cf. 5 ) to disposal.

Through the work of the pump 14 the cycle device, the pressure level of the fluid according to the TS diagram of 3 (considered theoretically or idealized) adiabatically and isentropically approached to a specified value and a defined volume flow of the fluid ensured. From the state point b to the state point c, there is a (theoretically or idealized) isobaric heat supply with evaporation and overheating. From the state point b ', the evaporation begins, which is completed when the state point b "is reached, and from the state point b" to the state point c, the vaporous fluid is overheated. The delivery of mechanical power by the expansion device 12 takes place by a (theoretically or idealized) isentropic relaxation from the state point c to the state point d. Depending on the type and structure of the expansion device 12 can now be relaxed until just before the steam area or in the wet steam area inside. From the state point d to the state point a, the fluid passes through the condenser 22 (considered theoretically or idealized) isobaric and isothermal liquefaction.

The aim of the consideration in the TS diagram is basically a maximization of the supplied heat from the state point b to the state point c and a minimization of the dissipated heat (q_ab) from the state point d to the state point a. The enclosed area from the state point a via the state points b and c to the state point d should be maximized in the intended temperature range. The efficiency of a Rankine process is thus visually as the ratio of the two surfaces in the 3 to interpret (η _th = 1 - (q_ab) / (q_zu)).

In order to maximize the heat supplied with the aim of achieving the highest possible efficiency of a real cycle process (Clausius-Rankine process) should also be achieved that in the evaporator 16 thermal energy transferred to the fluid of the cycle device as much as possible until reaching the expansion device 12 remains in the fluid. In order to do this in the cycle device of a drive system according to the invention according to, for example, the 1 and 2 To reach, it is envisaged that the evaporator 16 with the relatively widely spaced expansion device 12 connecting fluid line 28 as far as possible within a in the flow direction of the exhaust gas to the evaporator 16 subsequent exhaust pipe 30 the exhaust line is arranged. Thereby, the transition of heat energy from the heated by the fluid wall of the fluid conduit 28 be kept low on the environment, which on the one hand to a relatively small difference between the temperature of the fluid contained in the fluid line 28 and in the exhaust pipe 30 flowing exhaust gas and on the other hand to a flow around the inside of the exhaust pipe 30 located portion of the fluid line 28 by the exhaust gas at a flow rate that is relatively low compared to the vehicle speed and thus to the flow speed of the "wind" even at a relatively low speed of a vehicle comprising the drive system, by the outside of the exhaust pipe 30 are flowed around (if they are not shielded by other measures relative to the wind) or a component outside of the exhaust pipe 30 arranged fluid line 28 would flow around.

The drive systems according to the 1 and 2 differ with regard to the design of the evaporator 16 and a consequent different integration between the respective evaporator 16 and the associated expansion device 12 extending fluid line 28 in the exhaust pipe 30 , Both evaporators 16 are basically designed in the form of countercurrent heat exchangers, so that the fluid flowing in the circulatory system of the circulating process device, the evaporator 16 , each starting from a fluid inlet 32 of the evaporator 16 , In principle, or at least initially opposite to the direction with which the exhaust gas through the respective evaporator 16 is passed through, flows through. This can be done according to the evaporator 16 of the drive system according to the 1 cause a fluid outlet 34 at the upstream end of the evaporator with respect to the direction of flow of the exhaust gas 16 is arranged. To such a conventional evaporator 16 to integrate with the least possible design effort in an inventive drive system, it may be useful to one to the fluid outlet 34 subsequent first section of the fluid line 28 to arrange outside the exhaust line and the fluid line 28 just after the evaporator 16 in the exhaust pipe 30 to convict. However, this does not in the best possible way of the advantageous effect, by the inventive arrangement of the fluid line 28 inside the exhaust pipe 30 achievable, use made.

According to the 2 Therefore, it may be provided that the fluid, after it has first flowed through the evaporator 16 in the opposite direction to the exhaust gas, in this again up to a downstream end with respect to the flow direction of the exhaust gas and to the fluid outlet positioned therein within the exhaust line 34 the evaporator 16 is guided and there in the on the fluid outlet 34 connected fluid line 28 flows over.

The circulatory systems of the cycle processing apparatus according to 1 and 2 each still further include a respective expansion device 12 immediate bypass 36, with the subsets of the bypass 36 on the one hand and the associated expansion device 12 on the other hand to leading fluids each by means of a valve device 38 , For example by means of a 3-way valve, are adjustable. The valve device 38 can be controlled by means of a control device, not shown.

To describe the heat transfer of a tube flowed around in the longitudinal direction (eg the fluid line 28 ) generally applies: $$\dot{q}=\alpha \cdot {\left(T-T_{Wand}\right)}_{,}$$

In this case, α represents the heat transfer coefficient, T is the temperature of the gas flowing around the pipe (eg ambient air or exhaust gas) and T _{wall is} the temperature of the wall of the pipe, which can be equated with the temperature of the fluid flowing through the pipe.

λ stellt dabei die Wärmeleitfähigkeit des das Rohr umströmenden Gases, Nu die sogenannte Nußelt-Zahl und L die Länge des Rohrs dar.The heat transfer coefficient α is calculated according to: $$\alpha ={\frac{\lambda \cdot Nu}{L}}_{,}$$

λ represents the thermal conductivity of the gas flowing around the tube, Nu the so-called Nusselt number and L is the length of the tube.

mit dem Krümmungsparameter K: $$K=\upsilon \cdot {\frac{L}{r^2\cdot c}}_{,}$$

wobei v die kinematische Viskosität des das Rohr umströmenden Gases, r der Außenradius des Rohrs und c die Strömungsgeschwindigkeit des umströmenden Gases ist.For the Nusselt number applies (according to the VDI Heat Atlas): $$Nu=2\cdot \frac{0.55}{\sqrt{K}}+\frac{10}{9}\cdot \frac{0.95}{K^{0.1}}$$

with the curvature parameter K: $$K=\upsilon \cdot {\frac{L}{r^2\cdot c}}_{.}$$

where v is the kinematic viscosity of the gas flowing around the pipe, r is the outer radius of the pipe and c is the flow velocity of the gas flowing around.

The above equation for the Nusselt number applies to the Prandtl number Pr = 0.7 and the range for the curvature parameter K, which is between 10 ^-3 and 10 ⁴ .

To clarify the advantages of the inventive arrangement of the fluid line within the exhaust pipe, was compared based on the above calculation equations, which heat transfer coefficients are expected for the arrangement of the fluid line on the one hand inside and outside of the exhaust pipe. In the case of a (non-shielded) arrangement outside the exhaust pipe, the flow velocity of the gas flowing around the fluid line (ambient air) corresponds approximately to the vehicle speed. In an arrangement within the exhaust pipe, however, the flow rate of the exhaust gas in the exhaust pipe is relevant.

wobei ṁ_Abgas der Massenstrom des Abgases durch das Abgasrohr, ρ_Abgas die Dichte des Abgases und d_Abgasrohr der Innendurchmesser des Abgasrohrs ist.For the flow rate of the exhaust gas in the exhaust pipe, the following applies: $$c={\frac{4\cdot {\dot{m}}_{AbGas}}{{\rho }_{AbGas}\cdot \pi \cdot d_{AbGasrOHr}}}_{.}$$

where ṁ _{exhaust gas is} the mass flow of the exhaust gas through the exhaust pipe, ρ _{exhaust gas is} the density of the exhaust gas and d _{exhaust pipe is} the inner diameter of the exhaust pipe.

The comparison shows that the usual design of a drive system for a motor vehicle can be expected that even at a relatively low vehicle speed, the flow velocity of the exhaust gas is less than the vehicle speed, as shown in FIG. 4 for a case example and for three vehicle speeds v _Vehicle in the amount of 50 km / h, 95 km / h and 130 km / h is shown. In this case, the curve shown by a solid line shows a flow around the fluid line 28 by the ambient air, ie in a non-shielded arrangement outside the exhaust pipe 30 , And the dashed curve shown a flow around the exhaust, ie in an inventive arrangement of the fluid line within the exhaust pipe 30 , On the horizontal axis, the flow velocity v _Gas of the gas flowing around the fluid line (ambient air or exhaust gas) in km / h and on the vertical axis of the resulting heat transfer coefficient α in W / K is shown. In the considered speed range, the exhaust gas temperatures would be behind the evaporator 16 typically in the range of 80 ° C to 130 ° C.

The 4 illustrates that the heat transfer coefficient a, in each case based on a defined vehicle speed, by the arrangement of the fluid line 28 inside the exhaust pipe 30 significantly reduced.

For the creation of the diagram according to the 4 the following parameters were chosen: r = 6 mm; L = 1 m and d _{exhaust pipe} = 0.065m.

LIST OF REFERENCE NUMBERS

10

internal combustion engine

12

expansion device

14

pump

16

Evaporator

18

combustion chamber

20

exhaust aftertreatment device

22

capacitor

24

surge tank

26

electric machine

28

fluid line

30

exhaust pipe

32

Fluid inlet of the evaporator

34

Fluid outlet of the evaporator

36

bypass

38

valve device

40

exhaust outlet

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102009028467 A1 [0003]
• WO 2012/025776 A1 [0004]
• DE 69524414 T2 [0005]
• DE 102012113092 A1 [0006]
• DE 602005001788 A1 [0006]
• DE 102016100298 A1 [0006]

Claims (6)

Drive system for a motor vehicle with an internal combustion engine, which comprises an internal combustion engine (10) and an exhaust line, via which exhaust gas from the internal combustion engine (10) can be discharged, and with a cycle device, wherein the cycle device comprises a circulation system for a fluid, in which - an evaporator (16) integrated in the exhaust line of the internal combustion engine for evaporating the fluid, - an expansion device (12) for expanding the fluid, - a condenser (22) for condensing the fluid and - a pump (14) for conveying the fluid in the The evaporator (16) and the expansion device (12) are integrated into the drive system at a distance from each other and connected to each other by a fluid line (28), characterized in that the fluid line (28) at least partially within an exhaust pipe (30) of the Exhaust line is guided. Drive system according to Claim 1 , characterized in that the fluid line (28), starting from the evaporator (16), is guided within the exhaust pipe (30) in the direction of an exhaust gas outlet (40) of the exhaust gas line. Drive system according to Claim 1 or 2 , characterized in that the evaporator (16) is integrated downstream of an exhaust aftertreatment device (20) in the exhaust line. Drive system according to one of the preceding claims, characterized in that a fluid outlet (34) of the evaporator (16), to which the fluid line (28) is connected, located within the exhaust pipe (28). Drive system according to one of the preceding claims, characterized in that the evaporator (16) is designed as a countercurrent heat exchanger. Motor vehicle with a drive system according to one of the preceding claims.

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