DE102021127949B4 - Drive arrangement for a mobile, mobile with the drive arrangement and method for exhaust gas purification in the drive arrangement and/or in the mobile - Google Patents

Abstract

Drive arrangement (1) for an automobile (2) with a first thermal conversion motor (3) for generating a first drive torque for the automobile (2), wherein the first conversion motor (3) has an exhaust outlet (6) for discharging exhaust gas from the first conversion motor (3), with a second thermal conversion motor (7), wherein the second conversion motor (7) has a gas inlet (9), with a generator (11), wherein the generator (11) is coupled to the second conversion motor (7) in terms of drive technology for converting the mechanical energy from the second conversion motor (7) into electrical energy, wherein the second conversion motor (7) is coupled exclusively to the generator (11) in terms of drive technology, so that all the mechanical energy from the second conversion motor (7) is conducted into the generator (11), wherein the exhaust outlet (6) is fluidically connected to the gas inlet (9) so that the second conversion motor (7) thermally converts the exhaust gas from the first conversion motor (3) converts.

Description

The invention relates to a drive arrangement for a mobile with exhaust gas purification. The invention further relates to a mobile with the drive arrangement and a method for exhaust gas purification in the drive arrangement and/or in the mobile.

• ▪ weitere Konzentration auf Real-Driving Emissions (RDE) sicherstellen
• ▪ Kraftstoff- und Technologieneutralität erreichen
• ▪ Beruhend auf einer ganzheitlichen Analyse auf Lebenszyklusbasis Gesetze erlassen

In its European Green Deal concept, the European Commission announced a new legislative proposal for stricter standards on pollutant emissions from cars, vans, buses and trucks for 2021. In order to sustainably improve European air quality, the Euro 7 regulation offers a unique opportunity to implement a regulatory framework taking into account the following overarching principles:

• ▪ ensure continued focus on Real-Driving Emissions (RDE)
• ▪ Achieve fuel and technology neutrality
• ▪ Legislate based on a holistic life cycle analysis

The announced, stricter Euro 7 emissions standard is likely to have a major impact on the choice of technology at a reasonable cost-benefit ratio. The expected increase in the complexity of exhaust gas aftertreatment will not be achievable in a cost-neutral manner. Consequently, a realistic implementation of the CO2 targets will most likely be achieved through greater use of e-fuels, hybrid drives (HEV) and, in the long term, through H2 technology in a carbon-neutral approach. Current studies and sales figures, as well as forecasts, point to a symbiosis of thermo-chemical energy conversion machines with electric drives and thus show the need to further reduce pollutant emissions from combustion engines.

Current regulations on pollutant emissions take into account unburned hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NO, NO2 - both collectively referred to as NOx -), particulate matter (mass: PM and number: PN) and CO2.

1. 1) Innermotorischen Maßnahmen, zur Absenkung der Rohemissionen
2. 2) Außermotorischen Maßnahmen in Form eines dem Motor nachgeschalteten Abgasnachbehandlungssystems.
3. 3) Eine Kombination aus 1) und 2).

When it comes to reducing pollutant emissions from combustion engines, a distinction is made between:

1. 1) Internal engine measures to reduce raw emissions
2. 2) Non-engine measures in the form of an exhaust aftertreatment system downstream of the engine.
3. 3) A combination of 1) and 2).

The combination of 1) and 2) also represents the state of the art for all mobile applications to meet current emission standards. As a rule, internal engine measures are used to try to reduce the raw emissions (engine-out) to such an extent that the downstream exhaust aftertreatment system does not become unnecessarily complex and expensive. Internal engine measures also include exhaust gas recirculation (EGR), which is often seen as a necessary evil. EGR reduces the oxygen content and the process temperature, which causes a reduction in NOx. The further reduction of NOx (referred to as deNOx technology) is usually carried out using selective catalytic reduction (SCR). The reducing agent used in the SCR is an aqueous urea solution with the commercial name AdBlue. Depending on the NOx concentration in the raw exhaust gas (engine-out) and the engine condition, AdBlue is injected to reduce it to nitrogen, carbon dioxide (CO2) and water. The resulting CO2 is an undesirable byproduct of the SCR technology and thus contributes to an increase in the CO2 emissions of the combustion engine.

The publication DE 24 04 492 A1 reveals an ammonia engine.

The publication EN 10 2013 202 803 A1 discloses an arrangement of internal combustion engines, which is designed in particular as a compound engine. In particular, it is proposed that the first and the second internal combustion engine be operated in parallel and/or in series with respect to an output. For this purpose, a corresponding clutch and/or transmission arrangement would preferably be provided.

The publication EN 10 2012 208 071 A1 discloses a drive system which is designed in particular as a ship's drive system. From the description it emerges that a first internal combustion engine is designed as the main engine for propelling the ship and a second internal combustion engine is designed as a drive engine of a generator set of the ship's drive system that is to be operated with diesel fuel. The second internal combustion engine has a branch line that connects the exhaust gas outlet of the second internal combustion engine to the air inlet of the first internal combustion engine, so that the exhaust gas emitted by the second internal combustion engine can be fed to the air inlet of the first internal combustion engine.

The object of the present invention is to propose a drive arrangement with improved exhaust gas behavior. This object is achieved by a drive arrangement with the features of claim 1, by an automobile with the features of claim 8 and by a method for exhaust gas purification with the features of claim 9. Preferred or advantageous embodiments emerge from the subclaims, the following description and the attached figures.

The subject matter of the invention is a drive arrangement which is suitable and/or designed for a mobile designed as an automobile. The mobile is designed in particular as a movable object, in particular a self-moving object.

In particular, the drive arrangement provides a total drive torque for the vehicle. In particular, the drive arrangement serves to accelerate and/or drive the vehicle to a speed greater than 10 km/h, preferably greater than 40 km/h.

The drive arrangement has a first thermal conversion engine. The first conversion engine is designed to generate a first drive torque for the vehicle. Optionally, the first drive torque can correspond to the total drive torque of the vehicle. The first conversion engine has an exhaust outlet for discharging exhaust gas from the first conversion engine.

The drive arrangement has a second thermal conversion motor, wherein the second conversion motor has a gas inlet. In particular, the gas inlet serves to take in gas, in particular with a proportion of ambient air, in order to enable thermal conversion, in particular combustion during thermal conversion.

The fuel of the first and/or the second conversion engine is in particular burned. The first and/or the second conversion engine is designed, for example, as an internal combustion engine. The first and/or the second conversion engine thermally converts a fuel in order to convert chemical energy into thermal energy and subsequently into mechanical energy.

Within the scope of the invention, it is proposed that the exhaust gas outlet is fluidically connected to the gas inlet, so that the second conversion engine thermally converts the exhaust gas from the first conversion engine, in particular co-converts it, in particular burns it.

Preferably, the entire and/or complete exhaust gas mass flow of the first conversion engine is conducted via the exhaust gas outlet and/or via the gas inlet into the second conversion engine for thermal conversion. In the event that the first conversion engine has exhaust gas recirculation, preferably the entire and/or complete non-recirculated portion of the exhaust gas mass flow of the first conversion engine is conducted via the exhaust gas outlet and/or via the gas inlet into the second conversion engine for thermal conversion. The thermal conversion of the exhaust gas in the second conversion engine corresponds in particular to exhaust gas purification by means of afterburning.

The drive arrangement can also comprise a plurality of such second conversion motors.

The invention considers that typical exhaust aftertreatment systems with an increasing number of components, actuators, sensors, etc. are highly complex and therefore have higher manufacturing costs. Furthermore, the active and passive components in typical exhaust aftertreatment systems lead to a limited service life of the components. It should also not be underestimated that the use of additional operating materials, such as uric acid ("AdBlue"), in the exhaust aftertreatment systems increases the proportion of CO2 in emissions. In contrast, the invention proposes replacing part or all of the exhaust aftertreatment system with the second thermal conversion engine. In particular, critical emissions, especially NOx, can be reduced through thermal conversion.

In a preferred implementation of the invention, the second conversion engine has a fuel supply for supplying ammonia or a precursor of ammonia. In particular, the ammonia or the precursor of ammonia forms a main fuel for the second conversion engine. A precursor of ammonia is understood to be, for example, uric acid or the known AdBlue mixtures. Optionally, hydrogen can be additionally supplied to the second conversion engine in order to improve combustion. A number of advantages can be exploited by using ammonia or a corresponding precursor of ammonia.

Ammonia can be considered a hydrogen carrier and used as a fuel. It is considered to be of long-term interest, especially as a fuel for maritime transport. Ammonia can be considered a so-called "e-fuel" because it can be produced by electrolysis of water and subsequent catalytic conversion of hydrogen and nitrogen (from the air) to ammonia. Unlike most other electrofuels, ammonia can be produced without using a carbon source. Only electricity, water and air are required. which is advantageous in many ways. The electricity could be generated from wind or hydropower or other sustainable sources, so that the ammonia produced is a sustainable fuel. In particular, ammonia burns during thermal conversion without producing CO2.

The fuel (NH3) of the second conversion engine also acts as a reducing agent for the NOx in the exhaust gas of the first conversion engine. The NOx are reduced to N2 by means of selective non-catalytic reduction (SNCR) in the combustion chamber(s) of the second conversion engine. This takes place according to the reaction: NH2 + NO → N2 + H2O.

According to the invention, the drive arrangement has a generator for converting mechanical energy into electrical energy. The generator is coupled to the second conversion motor in terms of drive technology. The second conversion motor therefore takes on the function of providing energy in addition to the function of cleaning exhaust gases. This can be particularly efficient in conjunction with ammonia or a precursor of ammonia as fuel for the second conversion motor, since ammonia has a similar calorific value to gasoline. The second conversion motor thus combines the tasks of an exhaust gas aftertreatment system and a "bottoming cycle" in the form of electricity generation. In this case, a "bottoming cycle" is a downstream process, designed as a thermodynamic process or cycle, in which electricity is generated from waste heat. The chemical energy during exhaust gas cleaning in the second conversion motor is therefore not released into the environment, but is converted into electrical energy via the detour of mechanical energy and reused in the vehicle.

The electrical energy obtained can be stored in an energy storage device, for example in an accumulator, or consumed.

According to the invention, the second conversion motor is exclusively coupled to the generator in terms of drive technology. The entire mechanical energy of the second conversion motor is thus passed on to the generator for conversion into electrical energy. This design simplifies the architecture of the drive arrangement, since the second conversion motor does not have to be integrated into a mechanical drive train of the drive arrangement.

In a preferred implementation of the invention, the second conversion engine is designed as a two-stroke engine. Two-stroke engines are characterized by low complexity, in particular no valves are required in two-stroke engines. By choosing the two-stroke engine as the second conversion engine, the complexity of the system technology for exhaust gas purification is thus further reduced.

In a possible development of the invention, the second conversion engine is designed as a centrifugal engine and/or as a rotary piston engine and/or as a circular engine. For example, this can be implemented as a Wankel engine.

• - einen scheibenförmigen Rotor mit einer ersten Drehachse, die rechtwinklig zur Ebene des Rotors steht und in einer Orientierungsebene liegt,
• - ein im Wesentlichen scheibenförmiges Schwingelement mit einer zweiten Drehachse, die in der Ebene des scheibenförmigen Schwingelements und in der Orientierungsebene liegt, wobei die zweite Drehachse einen Winkel mit der ersten Drehachse in der Orientierungsebene bildet;
• - ein im Wesentlichen kugelförmiges Gehäuse, das den Rotor und das Schwingelement umgibt und in Kombination damit vier (De)Kompressionskammern bildet;
• - einen Verbindungskörper, der den Rotor und das Schwingelement im Gehäuse relativ zueinander verschiebbar positioniert und die vier (De)Kompressionskammern abdichtet;

wobei die Vorrichtung ferner mit einem Kraftantrieb und einer mechanischen Verbindung zwischen dem Kraftantrieb und dem Rotor versehen ist, wobei der Kraftantrieb konfiguriert ist, um Kraft an die Rotationsmaschine zu liefern oder aufzunehmen.Particularly preferably, the second conversion motor is designed as a rotary machine for compression and decompression. Preferably, the rotary machine comprises

• - a disc-shaped rotor with a first axis of rotation which is perpendicular to the plane of the rotor and lies in an orientation plane,
• - a substantially disc-shaped oscillating element with a second axis of rotation lying in the plane of the disc-shaped oscillating element and in the orientation plane, wherein the second axis of rotation forms an angle with the first axis of rotation in the orientation plane;
• - a substantially spherical housing surrounding the rotor and the oscillating element and forming in combination four (de)compression chambers;
• - a connecting body which positions the rotor and the oscillating element in the housing so that they can be displaced relative to one another and seals the four (de)compression chambers;

the apparatus further comprising a power drive and a mechanical connection between the power drive and the rotor, the power drive configured to supply or receive power to the rotary machine.

In particular, the generator is integrated in the rotary machine, the generator having a stator section and a rotor section, the rotor section being driven by the rotor and the stator being arranged on the housing. Preferably, the rotary machine is designed as a two-stroke engine. In particular, the rotary machine is designed according to the WO 2012/ 002 816 A2 In this respect, reference is made to the application WO 2012/ 002 816 A2 the contents of which are hereby included in this application.

Optionally, the drive arrangement has an electric machine to drive the mobile. The electric machine provides a second drive torque for the vehicle, with the total drive torque being formed by the first drive torque and the second drive torque. The electric machine is supplied with electrical energy directly by the generator and/or indirectly via the energy storage device, or at least co-supplied. In this embodiment, the chemical energy from the fuel for the second conversion motor is used to drive the vehicle, so that the exhaust gas purification is carried out in a virtually energy-neutral manner.

In a first possible embodiment of the invention, the first conversion engine works with a fossil fuel. In particular, the fuel is diesel, gasoline or a natural gas, in particular methane. With these fuels, cleaning the exhaust gases of nitrogen oxides is particularly complex. In particular, it must be taken into account that methane is the main component of natural gas. In lean operation (increased excess air) of natural gas engines, methane slip (fuel that does not take part in combustion and escapes from the engine with the exhaust gases) represents a major challenge. This is because of the high activation temperature for methane oxidation. While other unburned hydrocarbons are oxidized in a conventional catalyst, the catalytic post-oxidation of methane is difficult. In the second conversion engine, the methane is given a second chance to react in the high-temperature gas phase oxidation.

In an alternative embodiment of the invention, the first conversion engine is based on a renewable fuel, in particular on the basis of hydrogen or eFuels. The combustion of renewable fuels produces a particularly high amount of NOx, which does not need to be eliminated in the near future in view of the planned legal regulations. Here, the invention helps to implement increased environmental and thus climate protection beyond the legal requirements.

A further object of the invention is formed by an automobile which has a drive arrangement as described above and/or according to one of the preceding claims.

In particular, the automobile is realized as a vehicle, wherein the total drive torque drives the vehicle. Particularly preferably, the vehicle is designed as a hybrid vehicle, wherein this has the additional electric machine for generating the second drive torque.

A further object of the invention is formed by a method for exhaust gas purification in the drive arrangement and/or in the mobile as an automobile as described above, wherein exhaust gases are generated in the first conversion engine and wherein the exhaust gases are thermally converted in the second conversion engine in order to carry out exhaust gas purification.

• 1 eine schematische Blockdarstellung von einem Mobil mit einer Antriebsanordnung als ein Ausführungsbeispiel der Erfindung.

Further features, advantages and effects of the invention emerge from the following description of a preferred embodiment of the invention and the attached figure. This shows:

• 1 a schematic block diagram of a mobile with a drive arrangement as an embodiment of the invention.

The 1 shows a schematic block diagram of a drive arrangement 1 for a mobile 2, wherein the mobile 2 is designed as an automobile, for example. The drive arrangement 1 has the function of providing a total drive torque for the mobile 2 so that it can accelerate to a driving speed.

The drive arrangement 1 has a first thermal conversion motor 3, wherein the first thermal conversion motor 3 is designed as an internal combustion engine. The first conversion motor 3 has the function of generating a first drive torque for the mobile 2. The first drive torque forms part of the total drive torque. In the first conversion motor 3, a thermal conversion of a fuel takes place, wherein the fuel is fed to the first conversion motor 3 from a tank 4. In addition, ambient air is optionally fed to the conversion motor 3 via a compressor 5. The fuel can, for example, be mixed with the compressed ambient air after the compressor 5 (intake manifold injection). Alternatively, the fuel can be injected directly into a combustion chamber of the conversion motor 3.

The tank 4 can contain gasoline, diesel, methane, hydrogen and/or artificial fuels, such as eFuels, as fuel.

The first conversion engine 3 has an exhaust outlet 6, wherein exhaust gases from the thermal conversion of the fuel from the first conversion engine 3 are discharged via the exhaust outlet 6.

The drive arrangement 1 has a second thermal conversion motor 7, wherein the second conversion motor 7 is also designed as an internal combustion engine. The second Conversion engine 7 is supplied with fuel via a second tank 8, the fuel in the second tank 8 being ammonia or a precursor of ammonia. Hydrogen can optionally be added as a supplement, but the ammonia or the precursor of ammonia forms the main fuel for the second conversion engine 7.

The second conversion engine 7 has a gas inlet 9, wherein the gas inlet 9 is optionally fluidically connected to the gas outlet 6 via an expander 10, so that the exhaust gases from the first conversion engine 3 are passed on to the second conversion engine 7 for thermal conversion. The compressor 5 and the expander 10 form a charging group, in particular a turbocharger, but this is optional. In particular, exhaust gases are mixed with the fuel from the second tank 8 and subsequently thermally converted, in particular burned.

The drive arrangement 1 has a generator 11, wherein the generator 11 is connected in terms of drive technology to the second conversion motor 7. In a specific embodiment, the generator 11 can be integrated in the second conversion motor 7.

By means of the fuel supplied from the second tank 8 and the exhaust gases from the first conversion engine 3 supplied via the gas inlet 9, the thermal conversion on the one hand ensures that the exhaust gases are cleaned and on the other hand, by converting the chemical energy of the fuel into thermal energy and subsequently into electrical energy via the generator 11, the exhaust gas cleaning through the thermal conversion of the exhaust gases is not an energetic loss process, but the chemical energy used in it is dissipated again as electrical energy via the generator 11.

The drive arrangement 1 has an electric machine 12, wherein the electric machine 12 provides a second drive torque, wherein the second drive torque forms part of the total drive torque. The first drive torque and the second drive torque can form the total drive torque in parallel or alternatively. The generator 11 is directly connected to the electric machine 12, so that the electrical current can be consumed directly by the electric machine 12. Alternatively, the generator 11 is indirectly connected to the electric machine via an energy storage device 13, so that electrical energy is initially temporarily stored and only subsequently released. It is also possible for a further electrical energy source or a further electrical energy storage device to be provided.

In particular, the disadvantages of exhaust gas aftertreatment should be largely eliminated. These are: complexity, costs, resources (precious metals), service life of components, large number of catalysts, sensors and actuators connected in series, complex control (which also intervenes in engine control) and additional operating materials (AdBlue) with CO ₂ contribution.

The drive arrangement 1 comprises the combination of a second conversion motor 7 and a generator 11, in particular designed as a compact motor-generator that has the function of an exhaust gas aftertreatment system and a "bottoming cycle". The motor-generator is connected downstream of the first conversion motor 3 as an internal combustion engine, which represents the main drive. The entire exhaust gas mass flow leaving the internal combustion engine is introduced into the motor-generator. The motor-generator consists, for example, of a spherical-like housing, with the stator of the generator 11 arranged in the equator of the housing. The rotor of the generator 11 represents the rotating motor. This means that all the work produced in the combustion chambers of the motor-generator is converted directly into electricity. The motor of the motor-generator ideally works according to the 2-stroke principle and sucks in the entire exhaust gas mass flow of the upstream main drive. The main drive can be operated with fossil or synthetic fuels. In contrast, ammonia (NH3), which could also be doped with hydrogen (H2), is injected into the motor-generator engine. Injection takes place either in the intake tract or directly in the combustion chamber. A combination of intake manifold and direct injection is also possible. The exhaust gases from the main drive contain not only CO2, H2O, N2 and residual oxygen (02) in the range of 1% to 15%, but also pollutants such as unburned hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NOx). HC and CO are oxidized to CO2 in the motor-generator engine. The fuel (NH3) of the motor-generator also acts as a reducing agent for the NOx. The NOx are reduced to N2 in the engine's combustion chambers by means of selective non-catalytic reduction (SNCR). This occurs according to the reaction: NH2 + NO → N2 + H2O. The motor-generator thus combines the tasks of an exhaust aftertreatment system and a “bottoming cycle” in the form of a serial hybrid system.

The main drive can be designed without internal engine measures for NOx reduction, in particular without EGR, and can be optimized for maximum efficiency. This increases its service life and reduces the acquisition and operating costs (cost of ownership). In addition, the power split between the main drive and the bottoming cycle can be optimized depending on the operating point and the required overall system power. This means that the CO2 emissions of the main drive can be reduced by at least the power share of the bottoming cycle. If, for example, 20% of the required power is provided by the motor-generator with a carbon-free fuel such as NH3, the CO2 emissions of the main drive, which burns a carbon-containing fuel, are reduced by the same percentage because this only has to provide 80% of the total power.

• ▪ Ersetzung eines Teils oder des gesamten Abgasnachbehandlungssystems und dessen Komplexität z.B. für EU7 und/ oder für Heavy-Duty, Off-Road, Marine-& Stationär Anwendungen ähnliche Emissionsnormen.
• ▪ Realisierung eines „bottoming cycle“ in einem kompakten Motor-Generator, welcher einem, mit fossilen und/oder kohlenstoffneutralen Brennstoffen betriebenen, Verbrennungsmotor nachgeschaltet wird.
• ▪ Der gesamte Abgasmassenstrom des vorgeschalteten Motors fließt durch einen oder mehreren parallelgeschalteten Motor-Generatoren zwecks Abgasreinigung und gleichzeitiger Stromerzeugung in einer Hybridstrategie für die Speisung von Elektromotoren oder zur Batteriespeicherung.
• ▪ Jeder nachgeschaltete Motor-Generator übernimmt die Reduktion der Emissionen, insbesondere von NOx, unverbrannten Kohlenwasserstoffen (HC), Kohlenmonoxid (CO), Ruß, aber auch von, noch nicht reglementierten, Zwischenprodukte wie Formaldehyd, etc. Dies wird durch eine exotherme Reaktion erzielt, bei der dem Abgasmassenstrom ein kohlenstoffneutraler Kraftstoff und zugleich Reduktionsmittel wie Ammoniak (NH3) zugefügt wird. Der kohlenstoffneutrale Kraftstoff wird entweder vorm Eintritt in den Motor-Generator mit dem Abgasstrom des Hauptantriebs vorgemischt oder wird direkt in die Brennkammer eingespritzt.
• ▪ Der nachgeschaltete Motor-Generator wird - idealerweise kugelförmig - sehr kompakt ausgeführt, sodass seine Skalierung, analog dem Hubraum des vorgeschalteten Motors, ohne Einbuße in Platzverhältnissen gestaltet werden kann. Somit bewirkt eine Verdopplung des Durchmessers vom Motor-Generator eine achtfache Vergrößerung seines Hubraums.
• ▪ Ein elektrisch-angetriebener Verdichter kann vom Motor-Generator elektrisch gespeist werden, um den Teillastbetrieb des Verbrennungsmotors zu unterstützen.
• ▪ Methan (CH₄) slip aus lean-burn Gasmotoren kann in dem Motor-Generator oxidiert werden und benötigt keinen aufwendigen Methan-Katalysator, insbesondere kann hier der Methanschlupf ohne Katalysator oder mit weniger Katalysatoraufwand gereinigt werden.

Important points are:

• ▪ Replacement of part or the entire exhaust aftertreatment system and its complexity e.g. for EU7 and/or for heavy-duty, off-road, marine & stationary applications similar emission standards.
• ▪ Realization of a “bottoming cycle” in a compact motor-generator, which is connected downstream of a combustion engine powered by fossil and/or carbon-neutral fuels.
• ▪ The entire exhaust gas mass flow of the upstream engine flows through one or more motor generators connected in parallel for the purpose of exhaust gas purification and simultaneous power generation in a hybrid strategy for feeding electric motors or for battery storage.
• ▪ Each downstream engine-generator is responsible for reducing emissions, particularly NOx, unburned hydrocarbons (HC), carbon monoxide (CO), soot, but also intermediate products that are not yet regulated, such as formaldehyde, etc. This is achieved through an exothermic reaction in which a carbon-neutral fuel and a reducing agent such as ammonia (NH3) are added to the exhaust gas mass flow. The carbon-neutral fuel is either premixed with the exhaust gas flow from the main drive before entering the engine-generator or is injected directly into the combustion chamber.
• ▪ The downstream motor generator is designed to be very compact - ideally spherical - so that its scaling can be designed analogously to the displacement of the upstream motor without sacrificing space. Thus, doubling the diameter of the motor generator results in an eightfold increase in its displacement.
• ▪ An electrically driven compressor can be electrically powered by the motor generator to support the partial load operation of the combustion engine.
• ▪ Methane (CH ₄ ) slip from lean-burn gas engines can be oxidized in the engine-generator and does not require a complex methane catalyst; in particular, the methane slip can be cleaned without a catalyst or with less catalyst effort.

List of reference symbols

1

Drive arrangement

2

Mobile

3

first conversion engine

4

first tank

5

compressor

6

Exhaust outlet

7

second conversion engine

8th

second tank

9

Gas inlet

10

Expanders (optional)

11

generator

12

electric machine

Claims (9)

Drive arrangement (1) for an automobile (2) with a first thermal conversion motor (3) for generating a first drive torque for the automobile (2), wherein the first conversion motor (3) has an exhaust outlet (6) for discharging exhaust gas from the first conversion motor (3), with a second thermal conversion motor (7), wherein the second conversion motor (7) has a gas inlet (9), with a generator (11), wherein the generator (11) is drive-coupled to the second conversion motor (7) for converting the mechanical energy from the second conversion motor (7) into electrical energy, wherein the second conversion motor (7) is drive-coupled exclusively to the generator (11), so that all of the mechanical energy from the second conversion motor (7) is conducted into the generator (11), wherein the exhaust outlet (6) is fluidically connected to the gas inlet (9) so that the second conversion motor (7) can extract the exhaust gas from the first conversion motor (3) thermally converted. Drive arrangement (1) according to Claim 1 , characterized in that the second conversion engine (7) has a fuel supply for supplying ammonia or a precursor of ammonia. Drive arrangement (1) according to one of the preceding claims, characterized in that the second conversion engine (7) is designed as a two-stroke engine. Drive arrangement (1) according to one of the preceding claims, characterized in that the second conversion motor (7) is designed as a spherical motor, wherein the spherical motor has a housing with a spherical housing interior, wherein a rotor is arranged in the housing interior, wherein a stator section of the generator (11) is connected to the rotor and/or is arranged in the housing interior. Drive arrangement (1) according to one of the preceding claims, characterized by an electric machine (12) for generating a second drive torque for the mobile (2), wherein the electric machine (12) is fed or co-fed indirectly and/or directly via the generator (11). Drive arrangement (1) according to one of the preceding claims, characterized in that the first conversion engine (3) has a fuel supply with a fossil fuel and/or is designed as a diesel or petrol or gas engine. Drive arrangement (1) according to one of the preceding claims, characterized in that the first conversion engine (3) has a fuel supply with a regenerative fuel and/or is designed as a hydrogen eFuel engine. Automobile (2), characterized by a drive arrangement (1) according to one of the preceding claims. Method for exhaust gas purification in the drive arrangement (1) according to one of the Claims 1 until 7 and/or in the automobile (2) according to Claim 8 wherein exhaust gases are generated in the first conversion engine (3) and wherein the exhaust gases are thermally converted in the second conversion engine (7).

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