DE102010029972A1 - Combustion engine drive assembly for e.g. motor car, has pump connected with input of expander, and electrical generator mechanically connected with expander driven shaft and electrically connected with electrolysis device - Google Patents

Abstract

The assembly (1) has a fuel circuit (2) with a combustion engine (4) e.g. 4 stroke petrol engine, for combustion of air and gas mixture. An exhaust outlet aperture (28) is connected with an input of an exhaust gas condenser (8). A water reservoir (9) is attached with an input of an electrolysis device (10). A cooling circuit (3) cools a photovoltaic active region with a heat exchanger (15). A pump (19) is connected with an input of an expander (16). An electrical generator (22) is mechanically connected with an expander driven shaft (17) and electrically connected with the electrolysis device.

Description

The present invention relates to an internal combustion engine drive assembly for a vehicle.

The currently commonly used combustion engines, especially classic two- or four-stroke engines, diesel engines and their embodiments with devices for directly or indirectly injecting the fuel as well as turbo-charged or exhaust gas-charged versions still have two major disadvantages. The first disadvantage is that a significant portion of the heat of the internal combustion engine escapes unused through the exhaust system. The second disadvantage is that a significant portion of the energy through the cooling system remains unused. Even with the largest two-stroke diesel engines, which are currently used in ships and are exposed due to the size ratios of ships only small mechanical losses, efficiencies of more than 0.5 currently can not be achieved.

One way to positively influence the engine efficiency through the use of solar energy, for example, in the document DE 101 42 778 A1 been described. Solar cells are attached to the straight surfaces of a motor vehicle. It is proposed to use the electric energy provided by the solar cells for the splitting of water into oxygen and hydrogen, in order to improve the engine efficiency by adding the recovered oxygen to the normal combustion air. The hydrogen is added to a catalyst to aid in the degradation of pollutants.

Furthermore, in the document DE 10 2006 035 759 A1 a method for the power supply of the drive and the auxiliary operations of vehicles described in which electrical and / or mechanical energy and / or heat energy from environmental and environmental influences are obtained. For example, it is proposed to use the solar radiation by means of solar cells to store the heat effect of the sun's rays or the heat of the ambient air or the heat loss of in-vehicle components in a heat storage and use as needed as heat.

The publication EP 1 454 042 B1 discloses a high efficiency gasoline engine that burns fuel with a pressurized mixture of steam and air. A portion of the thermal energy generated by the combustion is recovered and used to evaporate water into the pressurized air to produce a pressurized steam water vapor stream. After combustion, the water vapor contained in the exhaust gas stream is used to drive a turbine. The output power of the turbine can in turn be used to drive an electric generator or for coupling into the main output power of the engine, whereby the engine efficiency is improved. For heat recovery, essentially a Rankine cycle is used.

In a Rankine cycle, the pressure of a liquid is increased in a first step. In a second step, the liquid is heated and evaporated at a constant pressure. Then, in a third step, the steam drives a turbine, reducing the pressure and temperature of the steam. In a final, fourth step, the steam is condensed using a condenser at constant pressure and temperature. The resulting liquid is then available again for the first step, namely the pressure increase.

Finally, in the patent US 5,317,996 a rotary engine described which can be operated with different fuels such as propane, methane or hydrogen. When hydrogen is used as a fuel, it is proposed to split the water condensed from the exhaust gas stream into hydrogen and oxygen by means of a solar-powered electrolysis and to make it available to the engine for combustion again.

Against this background, the invention has set itself the task of providing an internal combustion engine drive arrangement in which the efficiency is increased again and is also particularly maintenance and environmentally friendly. This object is achieved by the features of claim 1.

It should be noted that the features listed individually in the following description can be combined with one another in any technically meaningful manner and show further embodiments of the invention. The description additionally characterizes and specifies the invention in particular in connection with the drawing.

The internal combustion engine drive arrangement according to the invention for a vehicle and in particular for a hybrid vehicle is essentially characterized by two independent fluid circuits: on the one hand, it has a fuel circuit and, on the other hand, a cooling circuit.

The fuel circuit is in an advantageous embodiment, a closed fuel circuit. He has an internal combustion engine for combustion a mixture of a gas containing at least hydrogen and air in a combustion chamber. Preferably, the gas has only hydrogen as fuel, but may also contain fractions of other rapidly combustible gases. The hydrogen and the air are suitably supplied to the combustion chamber of the internal combustion engine, where the fuel-air mixture is ignited and burns. For this purpose, corresponding inlet openings for the hydrogen or the air are provided on the internal combustion engine. The internal combustion engine is any suitable for the combustion of hydrogen combustion engine, for example, a gasoline engine in a rotary or rotary piston design.

After the burning. the burned, hot fuel-air mixture is expelled from the combustion chamber and flows into an engine exhaust device connected in fluid communication with the internal combustion engine on the output side. In the field of the engine exhaust device, the fuel circuit preferably has an exhaust gas condenser to recover the water contained as water vapor in the hot engine exhaust gas, which has been generated in the combustion chamber by the combustion of hydrogen and oxygen. As a heat sink for condensing the water, the interior of the vehicle is preferably used, that is, the heat extracted from the engine exhaust gas when condensing the water is available to the interior of the vehicle as heating heat. Alternatively or additionally, the heat of condensation can also be made available to the cooling circuit, for example for heating the working fluid circulating in the cooling circuit, as will be described in more detail later.

The recovered from the engine exhaust gas water is preferably collected in a container or a water storage. For this purpose, the exhaust gas condenser is connected on the output side fluid-conducting with the input of the water reservoir. The water reservoir is also the output side fluidly connected to the input of an electrolysis device. The electrolysis device serves to split the water provided by the water reservoir by means of electrical energy into hydrogen and oxygen. On the output side, an outlet opening for the hydrogen gas or the oxygen gas are respectively provided on the electrolysis device. The hydrogen outlet opening of the electrolyzer is fluidly connected to the hydrogen inlet port of the internal combustion engine. Thus, the hydrogen is provided to the internal combustion engine for re-combustion.

The fuel circuit is closed. Water provided by the water reservoir is split into hydrogen and oxygen by the electrolysis device, the hydrogen in the combustion chamber of the internal combustion engine is combusted with, for example, air present in the air to water or water vapor condensed by the exhaust gas condenser back to liquid water and the fuel circuit again Is made available. The internal combustion engine is connected on the output side fluid-conducting with the input of the exhaust gas condenser, the exhaust gas condenser is connected on the output side fluid-conducting with the input of the water storage, the water storage is connected on the output side fluid-conductively connected to the input of the electrolysis device and finally the hydrogen outlet of the electrolysis device is fluidly connected to the hydrogen inlet port of the internal combustion engine.

Since the fuel circuit is closed, no replenishment of the water is required, for example in the water tank. Further, since the combustion product of hydrogen-oxygen combustion is water that is collected after condensing and used again for combustion in the internal combustion engine, no conventional exhaust system such as an exhaust gas provided as in the internal combustion engines is required. The heat of condensation provided by the exhaust gas condensation furthermore represents a possibility of heating the interior of the vehicle without additional costs or without the use of additional energy resources, for example in winter.

The electrolysis performed on the vehicle side and the provision of the hydrogen thus obtained for combustion by the internal combustion engine offer the great advantage that altogether less fuel has to be carried in a fuel pressure vessel in order to achieve the same range of conventional vehicles with a hydrogen engine. Furthermore, the size of a entrained fuel pressure vessel can be reduced in this way due to the lower required fuel volume and / or reduce the pressure at which the hydrogen is stored in the fuel pressure vessel. A smaller fuel pressure vessel leads to a lower total weight of the vehicle and makes it possible to make the thus saved space available elsewhere or to build the vehicle smaller.

Furthermore, the internal combustion engine has a region to be cooled. The area to be cooled preferably comprises an engine cooling device and / or an engine exhaust device.

The internal combustion engine drive assembly according to the invention further comprises a cooling circuit for cooling the region of the internal combustion engine to be cooled. For this purpose, this has a heat exchanger, an expander, a capacitor and a pump on. On the output side, the pump is connected in a fluid-conducting manner to the input of the expander, the expander is connected on the output side to a fluid-conducting connection with the input of the capacitor, and the capacitor is connected on the output side to a fluid-conducting connection with the input of the pump. The region of the internal combustion engine to be cooled, namely the engine cooling device and / or the engine exhaust device, is in thermal communication with the heat exchanger of the cooling circuit, that is, the heat is transferred in the heat exchanger from the region of the internal combustion engine to be cooled to a working fluid of the cooling circuit.

With the cooling circuit according to the invention a complete Rankine cycle is performed. By means of the pump, which is for example a feed water pump, the working fluid, for example water, is compressed to a pressure which is higher than the atmospheric pressure. The working fluid is then heated with the aid of the heat released from the area to be cooled in the heat exchanger at constant pressure and thereby evaporated.

Compressing and vaporizing are the first two steps of a Rankine process. In the Rankine process, in a third step, the steam is expanded via an expander, which is preferably a turbine or steam turbine, thereby generating mechanical energy. The relaxed after leaving the expander working fluid is then re-liquefied in a fourth step of the Rankine process using the condenser (condenser). The liquefaction takes place especially at constant pressure and at a constant temperature. Subsequently, the liquefied working fluid is again compressed by means of the pump and passed into the heat exchanger.

The mechanical energy generated in the expander is provided by means of an expander output shaft. In a preferred embodiment of the invention, the Expanderabtriebswelle is connected to an electric generator. The Expanderabtriebswelle can also be used to drive the pump and / or additionally transmitted to the output of the engine by means of a suitable transmission. This increases the overall efficiency of the engine drive assembly. In principle, an efficiency far above 0.5 can be achieved with the internal combustion engine drive arrangement according to the invention.

In a further advantageous embodiment of the invention, the cooling circuit further comprises a Stirling engine, which is also in thermal communication with the area to be cooled of the internal combustion engine. Further, the Stirling engine is connected to the pump of the refrigeration cycle to drive them. In this way, part of the heat released by the area of the internal combustion engine to be cooled can be used to operate the pump, which further increases the overall efficiency of the internal combustion engine drive arrangement according to the invention.

The generator is preferably electrically connected to the electrolysis device. That is, the mechanical energy generated by the expander is converted by the generator into electrical energy, which is largely or completely used for the electrolysis of the electrolyzer. The generator is preferably also electrically connected to a vehicle battery. A portion of the electrically generated energy which may not be required for the electrolysis can be used to charge the vehicle battery. If required, the electrically generated energy can preferably also be made available to further electrical consumers of the vehicle.

In a further preferred embodiment of the invention, photovoltaically active areas, in particular solar cells, are arranged on suitable exterior vehicle surfaces. The solar cells are also preferably electrically connected to the electrolysis device, so that the electrical energy provided by the solar cells can be used for the electrolysis of the water stored in the fuel circuit. Advantageously, the area of the photovoltaically active region is as large as possible. It can be arranged at different locations of the vehicle outer surface and a plurality of photovoltaically active areas, which are electrically interconnected in a suitable manner to provide the combustion engine drive assembly according to the invention as large a total electrical power available. Thus, the implementation of the electrolysis of the operation of the internal combustion engine is decoupled and can be carried out, for example, at standstill of the vehicle or during parking.

Preferably, the electrolysis takes place in the internal combustion engine drive assembly according to the invention at all times. During standstill of the vehicle, that is, when the engine does not require fuel for combustion, the hydrogen produced by the electrolysis is stored in a fuel pressure vessel. For this purpose, the hydrogen outlet of the electrolysis device is fluidly connected to the input of a fuel storage pump, which directs the fuel under pressure in the fuel pressure vessel, so that it can be made available to the internal combustion engine for combustion at a later date. The fuel pressure vessel is connected on the output side fluid-conducting with the hydrogen inlet of the internal combustion engine.

In order to further increase the overall efficiency of the internal combustion engine drive arrangement according to the invention, it is provided in a preferred embodiment that the fuel storage pump is operated by the braking energy recovered and stored during braking of the vehicle during the drive. For this purpose, the internal combustion engine drive arrangement according to the invention is equipped with a brake energy recovery and storage device. For example, a mechanical compressor is driven during braking of the vehicle to compress a storage fluid in a storage container. When relaxing the compressed storage fluid stored in the storage fluid braking energy is converted into mechanical work, for example, to drive the fuel storage pump.

Furthermore, the photovoltaically active region is preferably electrically connected to the vehicle accumulator and / or further electrical consumers of the vehicle in order to also make available the generated electrical solar energy to them, for example for charging the accumulator.

In a further preferred embodiment of the invention, the oxygen obtained from the electrolysis device is metered into the air, which is supplied to the combustion engine for combustion. Thus, the normal air concentration, which is usually about 21%, can be further increased, enabling improved and more efficient combustion of the air-fuel mixture. Furthermore, can be reduced by the higher oxygen content of the fuel-air mixture nitrogen oxide emissions.

Further details and advantages of the invention will become apparent from the following, with reference to a single figure explained schematic representation of a preferred, not limiting the invention embodiment.

1 schematically shows an internal combustion engine drive arrangement according to the invention 1 which is essentially a fuel cycle 2 and a cooling circuit 3 having.

The illustrated fuel circuit 2 includes an internal combustion engine 4 , the input side, a hydrogen inlet opening 26 and an air inlet opening 27 having. In the described embodiment, the internal combustion engine 4 a hydrogen engine suitable for combustion of a mixture of hydrogen and air or oxygen.

The internal combustion engine 4 also has an engine output shaft 5 for delivering a mechanical power. An engine exhaust port 28 is fluid-conducting via an engine exhaust device 6 with the input of an exhaust gas condenser 8th connected. Further, an engine cooling device 7 fluid-conducting with corresponding combustion engine 4 provided inlet and outlet ports connected. The engine exhaust device 6 and the engine cooling device 7 Make a section of the engine to be cooled 4 represents.

The in 1 illustrated exhaust gas condenser 8th represents the heat of condensation obtained in the condensation process of the exhaust gas flow to the vehicle interior as heating heat available, which is indicated by the arrow 31 in 1 is indicated. On the output side is the exhaust gas condenser 8th fluid-conducting with the entrance of a water reservoir 9 connected. The water storage 9 the output side is fluid-conducting with the fluid inlet of an electrolysis device 10 connected. The electrolysis device 10 has at its fluid outlet a hydrogen outlet 29 and an oxygen outlet port 30 on. The electrolysis device 10 also has an electrical connection for the supply of electrical energy.

The hydrogen outlet 29 is for example via a switching valve 13 fluid conducting with the hydrogen inlet port 26 of the internal combustion engine 4 connectable. Further, the hydrogen outlet port 29 via the switching valve fluid-conducting with the input of a fuel storage pump 12 connectable, the output side in turn with the input of a fuel pressure tank 11 connected is. The fuel storage pump 12 is on the drive side with an in 1 Not shown, the brake energy recovery device connected, which may be mechanical and / or electrical type.

The fuel pressure tank 11 is also with a in the 1 Not shown filling opening provided to hydrogen, for example, from a hydrogen tank system in the fuel pressure vessel 11 fill. The output of the fuel pressure tank 11 is fluid-conducting with the hydrogen inlet opening 26 of the internal combustion engine 4 connected.

The oxygen outlet 30 the electrolysis device 10 is fluid-conducting with a metering valve 14 connected. The metering valve 14 also has an air supply 32 for supplying normal ambience. On the output side is the metering valve 14 fluid-conducting with the air inlet opening 27 of the internal combustion engine 4 connected.

The in 1 illustrated cooling circuit 3 has a heat exchanger 15 on. The heat exchanger 15 On the output side, it is fluid-conducting with the input of an expander 16 connected. In the illustrated Embodiment is the expander 16 a steam turbine. The expander 16 also has an expander output shaft 17 to deliver a mechanical power. The output side is the expander 16 fluid-conducting with the input of a capacitor 18 connected. The capacitor 18 the output side is fluid-conducting with the input of a pump 19 connected. The pump 19 Finally, the output side is fluid-conducting with the input of the heat exchanger 15 connected. in the cooling circuit 3 circulates a working fluid, which is water in the illustrated embodiment. However, any other working fluid could be used which is suitable for carrying out a Rankine cycle in the sense of the invention. The pump 19 is a feedwater pump in the described embodiment.

Furthermore, the cooling circuit 3 a Stirling engine 20 on. The Stirling engine 20 is in thermal communication with the heat exchanger 15 what through the arrows 21 in 1 is indicated. That is, from the heat exchanger 15 Heat is applied to the Stirling engine 20 transferred to power this. The Stirling engine 20 is on the output side with the pump 19 connected. The pump 19 However, it could also work with the expander output shaft 17 be connected and driven by this, which is indicated by the dashed arrow 33 in 1 is indicated.

As in 1 is shown, the heat exchanger is 15 in the described embodiment with the area to be cooled of the internal combustion engine 4 that is with the engine exhaust device 6 as well as with the engine cooling device 7 in thermal connection. That is, heat from both the engine exhaust device 6 as well as from the engine cooling device 7 on the in the cooling circuit 3 circulating working fluid is transferable.

The expander output shaft 17 is with an electric generator 22 connected. The generator 22 is electrically connected to the electrical system of the vehicle. About the electrical system is the generator 22 electrically with the electrolyzer 10 , a vehicle battery 24 and other electrical consumers 25 connected in the vehicle. Furthermore, with the vehicle electrical system also mounted on the outside of the vehicle solar cells as photovoltaic active areas 23 electrically connected.

For the operation of the internal combustion engine 4 this hydrogen is taken from the fuel pressure tank 11 and / or the electrolysis device 10 above the on the internal combustion engine 4 provided hydrogen inlet opening 26 fed. Likewise, the internal combustion engine 4 over the air inlet opening 27 Supplied with air. The air and the hydrogen are in the internal combustion engine 4 mixed into a fuel-air mixture. The fuel-air mixture is in a combustion chamber of the internal combustion engine 4 burned. In the embodiment described here, the air is via the metering valve 14 a suitable proportion of oxygen which is produced during the electrolysis in the electrolysis device 10 is generated, added. This increases the oxygen content of normal air, which is typically about 21%, which allows efficient combustion.

The heat generated by the combustion is on the one hand via the engine cooling device 7 and, on the other hand, the hot exhaust gas flow passing through the engine exhaust device 6 is routed from the internal combustion engine 4 led out and the cooling circuit 3 , in particular the heat exchanger 15 , made available. In the heat exchanger 15 finds a heat transfer from the engine cooling device 7 on the one hand and the engine exhaust device 6 on the other hand, in the refrigeration cycle 3 circulating working fluid instead. After the heat transfer in the heat exchanger 15 becomes the water vapor still contained in the exhaust gas stream in the condenser 8th condensed. The released heat of condensation is in the in 1 illustrated embodiment when needed as heating heat for heating the vehicle interior available.

The condensed water from the exhaust gas flow is collected and into the water reservoir 9 transported where it is for in the electrolysis device 10 performed electrolysis is available. The hydrogen produced by the electrolysis, as long as the hydrogen engine 4 is in operation, this again for combustion via the switching valve 13 fed. Thus, the fuel extraction from the fuel pressure tank can be 11 during operation of the internal combustion engine 4 to reduce.

At the times when the internal combustion engine 4 is not operated in, so if the vehicle is parked, for example, the electrolysis in the electrolysis device 10 nevertheless carried on. The electrical energy required for this purpose is from the electrical system of the vehicle and in particular from the photovoltaic active area 23 of the vehicle, that is, the solar cells attached to the vehicle outer surface. Since no hydrogen is needed for the combustion in this case, this is by means of the fuel storage pump 12 in the fuel pressure tank 11 pumped and stored. The fuel storage pump 12 is driven by means of an energy, which is provided from a brake energy recovery device, not shown. The braking energy of the vehicle is used during the drive to drive a mechanical compressor to the previously generated but during the brake / standstill phase when the engine is hot to generate generated hydrogen. In this way, regeneratively generated hydrogen is always available in addition to the originally refueled supply in order to further increase the overall efficiency of the internal combustion engine drive arrangement according to the invention.

The heat transfer from the engine cooling device 7 and the engine exhaust device 6 takes place at the in 1 illustrated embodiment such that compared to that of the engine exhaust device 6 transported heat lower temperature than that of the engine cooler 7 transported heat is used by means of the pump 19 compressed working fluid of the cooling circuit 3 in the heat exchanger 15 preheat. By means of the much hotter exhaust gas flowing through the engine exhaust device 6 is passed, the working fluid is then further heated and evaporated. The two-stage heat transfer, that is, the preheating and the subsequent heating and evaporation in the heat exchanger 15 , is in 1 by the motor cooling device successively arranged in the flow direction of the working fluid 7 and engine exhaust device 6 shown.

The generated water vapor gets into the turbine 16 headed and relaxed there, taking the turbine 16 is driven by means of water vapor. The expander output shaft 17 the turbine 16 is rotated by means of the water vapor in a rotary motion. The mechanical energy generated in this case can be both on the engine output shaft 5 of the internal combustion engine 4 be transferred, as well as to operate the pump 19 be used. In the illustrated example, however, the generated mechanical energy is used alone to power the generator 22 drive. The generated mechanical energy is therefore by means of the generator 22 converted into electrical energy.

That's the turbine 16 leaving working fluid, especially in the form of water vapor, is then in the condenser 18 directed. Inside the condenser 18 the working fluid is liquefied at constant pressure and temperature. Subsequently, the liquefied working fluid leaves the condenser 18 and becomes the pump 19 and is thus again available to the Rankine cycle. It should be noted that the heat of condensation that occurs during condensation in the condenser 18 and / or in the condenser 8th is obtained, optionally also for preheating the working fluid in the cooling circuit 3 can be used, as already mentioned above in connection with the heat transfer of the engine cooling device 7 has been described.

As in 1 is shown, is the Stirling engine 20 also in thermal communication with the heat exchanger 15 what through the arrows 21 is indicated. The Stirling engine 20 So it is through a part of the heat exchanger 15 driven heat and thus uses the mechanical energy generated in this case to drive the pump 19 ,

The one from the turbine 16 over the output shaft 17 powered generator 22 provides the generated electrical power to the electrical system of the vehicle. In particular, the generated electrical energy is used to the electrolysis device 10 be supplied with electrical energy to carry out the electrolysis. Furthermore, however, the generated electrical energy also becomes other electrical consumers 25 provided in the vehicle and in particular also for charging the vehicle battery 24 used.

In a preferred embodiment, the internal combustion engine drive arrangement according to the invention is used with a hydrogen combustion engine in a hybrid vehicle with serial or parallel hybrid drive. In such a vehicle, the advantages of the internal combustion engine drive arrangement according to the invention with those of a conventional electric drive complement each other in an ideal manner, in particular, the hybrid vehicle of this type has almost no polluting emissions and uses the energy resources used in an optimal manner.

LIST OF REFERENCE NUMBERS

1

Combustion engine power system

2

Water cycle

3

Cooling circuit

4

internal combustion engine

5

Engine output shaft

6

Engine exhaust device

7

Engine cooling apparatus

8th

flue gas condenser

9

water-tank

10

electrolyzer

11

Fuel pressure vessel

12

Fuel storage pump

13

switching valve

14

metering valve

15

heat exchangers

16

expander

17

Expander output shaft

18

capacitor

19

pump

20

Stirling engine

21

heat transfer

22

generator

23

Photovoltaically active area

24

Fahrzeugakkumulator

25

Electric consumer

26

Hydrogen inlet port

27

Air inlet opening

28

exhaust outlet

29

hydrogen outlet

30

oxygen outlet

31

heating

32

air supply

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 10142778 A1 [0003]
• DE 102006035759 A1 [0004]
• EP 1454042 B1 [0005]
• US 5317996 [0007]

Claims (1)

Internal combustion engine drive assembly ( 1 ) for a vehicle, in particular for a hybrid vehicle, comprising a fuel circuit ( 2 ) with an internal combustion engine ( 4 ) for combustion of a mixture of an at least hydrogen-containing gas and air, an exhaust gas condenser ( 8th ) for recovering the water contained in the engine exhaust, a water reservoir ( 9 ) for providing the water for the fuel circuit ( 2 ) and an electrolysis device ( 10 ) for producing hydrogen, wherein an exhaust gas outlet opening ( 28 ) of the internal combustion engine ( 4 ) in fluid communication with the inlet of the exhaust gas condenser ( 8th ), the exhaust gas condenser ( 8th ) on the output side fluid-conducting with the input of the water reservoir ( 9 ), the water reservoir ( 9 ) on the output side fluid-conducting with the input of the electrolysis device ( 10 ) and a hydrogen outlet ( 29 ) of the electrolysis device ( 10 ) with a hydrogen inlet opening ( 26 ) of the internal combustion engine ( 4 ), wherein the internal combustion engine ( 4 ) further comprises a region to be cooled, comprising an engine exhaust device ( 6 ) and / or an engine cooling device ( 7 ), a cooling circuit ( 3 ) for cooling the area to be cooled with a heat exchanger ( 15 ), an expander ( 16 ), which has an expander output shaft ( 17 ), a capacitor ( 18 ) and a pump ( 19 ), whereby the pump ( 19 ) on the output side fluid-conducting with the input of the expander ( 16 ), the expander ( 16 ) on the output side fluid-conducting with the input of the capacitor ( 18 ) and the capacitor ( 18 ) on the output side fluid-conducting with the input of the pump ( 19 ), and an electric generator ( 22 ) connected to the expander output shaft ( 17 ) is mechanically connected and with the electrolyzer ( 10 ) is electrically connected.

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