DRIVE SYSTEM FOR A VEHICLE

Description

[0001] The invention relates to a drive system for a vehicle, a method for operating a drive system, a vehicle, and the use of such a drive system in a vehicle. A drive system according to the preamble of claim 1 is known, for example, from WO 2008 / 087685 A2.

[0002] Current developments regarding climate-friendly mobility and the technical advancement of purely electric drive systems have produced solutions in which an internal combustion engine drives a generator. This, in turn, feeds a drive battery with generated electrical energy, which then supplies the stored electrical energy to at least one electric motor for driving, for example, the wheels of a passenger vehicle. Such power generators are generally known from the prior art. In particular, DE 10 2014 115 042 A1, DE 10 2014 115 041 A1, DE 10 2014 115 044 A1, and EP 2 633 166 B1, all of which originate from the applicant, describe such power generators. The known power generators have a wide range of applications. They are preferably used in hybrid vehicles.

[0003] From the aforementioned WO 2008 / 087685 A2, a propulsion system for vehicles is known, comprising a gas turbine with a compressor and a drive turbine, with a burner arranged between the compressor and the drive turbine. The system further comprises an exhaust gas reformer connected to the burner and a generator coupled to the gas turbine. The system additionally comprises a battery that is charged during start-up of the propulsion system.

[0004] JP 2001 221062 A describes a low-power gas turbine used as a propulsion system for a vehicle. The gas turbine incorporates a plasma reactor as its core unit to achieve high performance and a long service life while avoiding air pollution.

[0005] The invention is based on the object of providing a drive system for a vehicle with a completely new approach that is climate-friendly and efficient to operate. The invention is further based on the object of providing a method for operating a drive system, a vehicle, and the use of a drive system in a vehicle.

[0006] According to the invention, this object is achieved with regard to the drive system by the subject matter of claim 1. With regard to the method, the vehicle and the use, the above-mentioned object is achieved by the subject matter of claim 9 (method), claim 13 (vehicle) and claim 14 (use).

[0007] Specifically, the object is achieved by a drive system for a vehicle, in particular for a hybrid vehicle, with at least one power unit and at least one drive battery, which are electrically coupled to one another, wherein the power unit comprises: at least one gas turbine comprising at least one first compressor for compressing intake combustion air, at least one turbine for driving the first compressor, and at least one combustion chamber arranged therebetween for combusting an air / fuel mixture, which is fluidly connected to the first compressor and the turbine; at least one reformer for reforming a vaporized fuel, in particular vaporized methanol, into a synthesis gas, wherein the reformer is connected to the combustion chamber for supplying the synthesis gas; and at least one generator mechanically coupled to the gas turbine for absorbing and / or introducing a rotary motion, The drive battery is electrically connected to the generator of the power unit and is adapted to supply at least one electric motor for driving the vehicle and / or the generator with electrical energy. The gas turbine comprises at least one guide device for directing the flow of the combusted air / fuel mixture, in particular exhaust gas, which is arranged in the flow direction between the combustion chamber and the turbine. The guide device is arranged upstream of the reformer in a fuel flow direction and is adapted to absorb heat from the combusted air / fuel mixture during operation and to vaporize a liquid fuel, in particular liquid methanol, through heat transfer.

[0008] The drive system according to the invention is based on the basic idea of ​​generating electrical energy for an electrically powered vehicle using a gas turbine and a generator. The gas turbine and the generator form a turbine-generator unit. The turbine-generator unit serves only to generate electrical energy, so that the actual drive power for the vehicle is purely electric. The drive system according to the invention is versatile. In particular, the drive system can be used in hybrid vehicles, for example, a passenger car, a truck, a bus, a watercraft or boat, and / or an aircraft.

[0009] The use of a reformer adapted to reform a vaporized fuel is particularly advantageous. This allows the vaporized fuel to be used to produce a synthesis gas with a higher calorific value than the starting material. This increases the efficiency of the gas turbine and thus of the entire power plant. The drive system according to the invention thus exhibits increased efficiency through the combination of the gas turbine with the reformer. The vaporized fuel particularly preferably consists of vaporized methanol. At least two types of synthesis gas with increased calorific values ​​can be produced from the vaporized methanol by the reformer. This increases the operating variability of the gas turbine.

[0010] Methanol is a very easy-to-produce and synthesize fuel based on hydrocarbons and / or alcohols. In particular, the CO2 footprint of vehicle operation can be reduced or offset if the methanol is produced using renewable energy. This enables particularly climate-friendly operation of a vehicle equipped with this drive system.

[0011] The generator is mechanically coupled to the gas turbine to absorb the rotational movement of the gas turbine or to set the gas turbine in rotation. For this purpose, the generator can be directly connected to a turbine shaft of the gas turbine. More specifically, the generator can be directly connected to the turbine shaft via its generator shaft. This has the advantage that the gas turbine's speeds can be directly converted into electrical energy by the generator without any transmission losses. In particular, it is possible to directly convert speeds of up to 100,000 rpm (revolutions per minute) into electrical energy. This has the advantage that large, heavy gearboxes are no longer required.

[0012] Alternatively, the generator can be mechanically coupled to the gas turbine via a gearbox. This allows the gas turbine's speed to be adjusted to meet specific requirements, enabling the use of smaller generators. It is possible for the power unit to have several, particularly two, generators that are mechanically coupled to the gas turbine to absorb and / or generate rotary motion.

[0013] Generally, the generator converts the rotational movement of the gas turbine into electrical energy, which is stored in the traction battery. This applies to normal operation of the power generator. The generator can also be operated as a motor. In other words, the generator can operate as an electric motor that drives the gas turbine. This is necessary during the start-up phase of the gas turbine to set the gas turbine in rotation and thus start the gas turbine process (normal operation). Once this has been achieved, the generator switches from motor operation to generator operation and then generates electrical energy.

[0014] Since the generator is electrically connected to the drive battery, the latter supplies the generator with electrical energy for engine operation during the start-up phase of the gas turbine. During normal operation, the drive battery absorbs the electrical energy generated by the generator and stores it. The drive battery provides the electrical energy to an electric motor for driving the vehicle. For this purpose, the drive battery is preferably connected to the electric motor. In general, it is possible for the drive battery to be connected to several electric motors for driving the vehicle. The drive system according to the invention can also comprise several drive batteries that are electrically connected to the generator. This enables the use of several smaller batteries.

[0015] During operation, a first compressor of the gas turbine draws in combustion air and compresses it. The combustion air is air that is drawn in from the environment of the gas turbine. The compressed combustion air is then fed to the combustion chamber. Parallel to the compression of the combustion air, the reformer reforms the vaporized fuel. The synthesis gas produced during reforming is fed to the combustion chamber as gaseous fuel. In the combustion chamber, the compressed combustion air and the gaseous fuel or the produced synthesis gas mix to form an air / fuel mixture, which is ignited in the combustion chamber. The combusted air / fuel mixture then flows into the turbine as exhaust gas and drives the turbine via turbine blades, to which at least one generator is mechanically coupled.

[0016] The drive system is preferably a serial hybrid drive system. In other words, the turbine-generator unit is connected in series with the drive battery and the at least one electric motor. During operation, the turbine-generator unit does not directly drive the vehicle, but merely provides electrical energy, which is then drawn on by the at least one electric motor via the drive battery as a buffer storage and converted into kinetic energy of the vehicle.

[0017] Another advantage of the serial hybrid drive system is that, unlike purely electric drive systems, the turbine-generator unit allows for a smaller drive battery. Since the drive battery accounts for a large portion of the vehicle's weight, this allows for weight reduction.

[0018] For the implementation of a serial hybrid drive system, it is particularly preferred if the gas turbine of the turbine-generator unit exclusively drives the at least one generator. If the vehicle is equipped with a turbine-generator unit that has several, in particular two, generators, the gas turbine can exclusively drive the generators.

[0019] The guide device is preferably arranged directly upstream of the turbine blades in the flow direction. The guide device is preferably arranged at the turbine inlet. The guide device is arranged upstream of the reformer in the fuel flow direction. The guide device is preferably at least one guide vane for flow guidance.

[0020] The guide device fulfills a dual function. On the one hand, the guide device directs the flow of the combusted air / fuel mixture into a predetermined flow path before entering the turbine. For example, the guide device converts the potential energy from the combustion chamber into kinetic energy, which is then converted into torque by the turbine. On the other hand, the guide device provides heat transfer from the hot exhaust gas to the liquid fuel, through which the liquid fuel evaporates. For this purpose, the guide device is preferably connected to the combustion chamber and the turbine by at least one first flow path, and the guide device is connected to a fuel supply, in particular a fuel tank, and the reformer by at least one second flow path.

[0021] The guide vane must withstand high thermal loads during operation. To protect the guide vane from thermal overload, it is designed to be cooled with liquid fuel. The liquid fuel is preferably liquid methanol or a liquid methanol / water mixture. The liquid fuel cools the guide vane through contact and evaporates in the process. This is also known as evaporative cooling. The vaporized fuel is then fed to the reformer. Cooling the guide vane thus increases the service life of the guide vane and evaporates the liquid fuel for subsequent synthesis gas production. This process corresponds to thermochemical recuperation.

[0022] Particularly preferably, the guide device has a plurality of guide vanes, each having at least one passage, which is connected to a supply line for liquid and / or pre-evaporated fuel and a discharge line for vaporized fuel. In other words, each guide vane has at least one passage. The passage preferably forms a heat transfer region for vaporizing the liquid fuel. The passage preferably has at least one surface for heat transfer. The guide vanes are preferably hollow. The passage can be slot-shaped. The passage can additionally or alternatively be formed by a bore. The passage through the guide vanes enables heat transfer from all sides transverse to the fuel flow direction.It is advantageous here that the guide vanes have as large a surface area as possible to absorb heat from the exhaust gas and transfer it to the flowing fuel for evaporation.

[0023] In a preferred embodiment, the reformer is adapted to produce from the vaporized fuel, in particular the vaporized methanol, a synthesis gas with a calorific value that is 10 percent to 25 percent, in particular 13 percent to 20 percent, higher than the calorific value of the vaporized fuel. The calorific value of the synthesis gas may be 12 percent to 23 percent, in particular 14 percent to 21 percent, higher than the calorific value of the vaporized fuel. Preferably, the calorific value of the synthesis gas may be 16 percent to 19 percent, in particular 17 percent or 18 percent, higher than the calorific value of the vaporized fuel.

[0024] For a synthesis gas produced by the reformer from vaporized methanol, the calorific value is 15 percent to 18 percent, particularly preferably 18 percent to 20 percent higher, than the calorific value of the vaporized methanol before reforming.

[0025] The reaction equation (1st equation) for methanol to synthesis gas is as follows: 1. Equation: CH 4 O → 2H 2 + CO.

[0026] For a synthesis gas produced by the reformer from a vaporized methanol / water mixture, the calorific value is 10 percent to 12 percent, preferably 12 percent to 14 percent, and particularly preferably 13 percent higher than the calorific value of the vaporized methanol / water mixture before reforming. The water content of the methanol / water mixture can be added to the methanol before vaporization or after vaporization.

[0027] The reaction equation (2nd equation) for the methanol / water mixture to produce synthesis gas is as follows: 2nd equation: CH 4 O + H 2 O → CO 2 + 3H 2 .

[0028] The following table (Table 1) lists the calorific values ​​and molecular weights of the vaporized fuels, i.e., the vaporized methanol and vaporized methanol / water mixture, and the resulting synthesis gases. Based on the calorific values ​​shown therein in kJ / mol (kilojoules per mole), the calorific value increases described above can be calculated in percent. Table 1: calorific value Molecular weight calorific value [MJ / kg] [g / mol] [kJ / mol] COH4 19,9 32 637 CO 10,1 28 283 H2 120 2 240 2H2+CO 763 3H2 720

[0029] The power generator can have at least one condensation unit for generating condensate from an exhaust gas stream of the gas turbine, which is connected to the gas turbine on the exhaust side or arranged on the gas turbine. The condensation unit can be arranged on the exhaust side of the gas turbine. In addition, the power generator can comprise at least one feed unit for feeding the condensate to the liquid and / or vaporized fuel. Using the exhaust gas stream consisting of the combusted air / fuel mixture, the condensation unit condenses water, which can then be fed to the methanol by the feed unit to form a methanol / water mixture. In this embodiment, the heat of the exhaust gas stream is used to extract water for the vaporized fuel mixture to be reformed. Separate components for condensate extraction can therefore be omitted, reducing system complexity.

[0030] The power generator preferably has at least one electric evaporator for evaporating the liquid fuel, particularly during the start-up phase of the power generator, which is arranged upstream of the guide device in the fuel flow direction. During the start-up phase of the gas turbine, the guide device has a temperature that is not yet sufficient for evaporation of the liquid fuel. During this phase, the electric evaporator is used, evaporating the liquid fuel upstream of the guide device in the flow direction. During normal operation, the electric evaporator is preferably deactivated. This ensures in a simple manner that the gas turbine process starts up.

[0031] In one embodiment, the power generator has at least one second compressor, in particular an exhaust gas turbocharger, and at least one air cooler, which are arranged in the flow direction of the combustion air between the first compressor and the combustion chamber. The air cooler is preferably connected upstream of the second compressor. The air cooler is preferably an air / air cooler. In other words, the air cooler cools the combustion air compressed by the first compressor using ambient air flowing through the air cooler. After the first compression stage by the first compressor, a second compression stage is carried out by the second compressor. In other words, the two compressors form a second-stage compression of the combustion air before it enters the combustion chamber. The air cooler provides intermediate cooling for the combustion air.The two-stage compression of the combustion air with intermediate cooling achieves an efficiency increase of the gas turbine of approximately 10 percent.

[0032] In a further embodiment, the power generator has at least one heat exchanger, in particular an exhaust gas heat exchanger, for preheating compressed combustion air, which is arranged between the first compressor and the combustion chamber. Alternatively, the heat exchanger, in particular an exhaust gas heat exchanger, for preheating compressed combustion air can be arranged between the second compressor and the combustion chamber. The heat exchanger is preferably connected to the gas turbine on the exhaust side for heat transfer. The heat exchanger uses the temperature of the exhaust gas stream or the combusted air / fuel mixture to heat the compressed combustion air before it enters the combustion chamber. This thermal recuperation achieves an efficiency increase of the gas turbine of 10 percent to 15 percent.

[0033] The heat exchanger is preferably adapted to heat the compressed combustion air to at least the ignition temperature of the synthesis gas generated by the reformer. Additionally or alternatively, the combustion chamber is adapted to accelerate the combustion air to a velocity higher than the flame velocity of the synthesis gas to be combusted. These two requirements are necessary to enable flameless oxidation in the combustion chamber, which has the advantage that virtually no nitrogen oxides are produced during the combustion of the air / fuel mixture.

[0034] Preferably, at least one electric motor is provided for driving the vehicle, in particular a hybrid vehicle, which is connected to the drive battery. The electric motor is provided as the drive motor for the vehicle. It is possible for several electric motors to be provided for driving the vehicle, which are electrically connected to the drive battery or several drive batteries.

[0035] According to a secondary aspect, the invention relates to a method for operating a drive system, in particular a drive system according to the invention, which has at least one power generator with at least one gas turbine, at least one reformer and at least one generator, and at least one drive battery electrically connected to the power generator, the method comprising the following steps: Suction of combustion air through at least one first compressor of the gas turbine and compression of the combustion air; supplying the compressed combustion air to a combustion chamber arranged between the first compressor and a turbine of the gas turbine; vaporization of a liquid fuel, in particular liquid methanol, through at least one guide device which, during operation, absorbs heat from a combusted air / fuel mixture from the combustion chamber and transfers it to the fuel flowing through it; supplying the vaporized fuel to the reformer, which converts the vaporized fuel into a synthesis gas and supplies it to the combustion chamber; burning the air / fuel mixture in the combustion chamber and driving the turbine of the gas turbine; transferring a rotary motion from the gas turbine to the generator to generate electrical energy;and storing the electrical energy in the traction battery, which is electrically connected to the generator, to supply at least one electric motor and / or the generator with electrical energy. ;

[0036] In a preferred embodiment of the method according to the invention, the compressed combustion air is further compressed by at least one second compressor, in particular an exhaust gas turbocharger, of the power generator before being fed to the combustion chamber. Before further compression, the combustion air is cooled by at least one air cooler arranged between the first compressor and the second compressor in the direction of combustion air flow.

[0037] In one embodiment of the method according to the invention, the drive system comprises a heat exchanger which heats the compressed combustion air at least to an ignition temperature of the synthesis gas produced by the reformer.

[0038] In a further embodiment of the method according to the invention, the combustion chamber accelerates the combustion air to a speed that is higher than a flame speed of the synthesis gas to be burned.

[0039] According to a further subordinate aspect, the invention relates to a vehicle, in particular a hybrid vehicle, with at least one drive system according to the invention and at least one electric motor which is connected to the drive battery of the drive system for driving the vehicle.

[0040] According to a further subordinate aspect, the invention relates to the use of at least one drive system according to the invention in a vehicle, wherein the power unit generates electrical energy and the drive battery stores the electrical energy, wherein the drive battery is connected to at least one electric motor for driving the vehicle. The vehicle can be a passenger car (PCA) and / or a commercial vehicle (Truck) and / or a bus. Alternatively, the drive system according to the invention can be used in an aircraft and / or a boat.

[0041] Regarding the advantages of the method, the vehicle, and the use, reference is made to the advantages explained in connection with the drive system. Furthermore, the method and the vehicle may alternatively or additionally have individual or a combination of several features previously mentioned with regard to the drive system.

[0042] The invention will be explained in more detail below with reference to the accompanying drawings. The illustrated embodiments represent examples of how the drive system according to the invention can be designed.

[0043] In these show, Fig. 1 is a schematic representation of a drive system according to a preferred embodiment of the invention; Fig. 2 is a perspective representation of a guide device of the drive system according to Fig. 1 ; Fig. 3 a partial section of a turbine with inserted guide device of the drive system according to Fig. 1 ; Fig. 4 shows a schematic representation of a drive system according to a further embodiment of the invention; and Fig. 5 shows a schematic representation of a drive system according to a further embodiment of the invention.

[0044] Fig. 1shows a drive system 100 according to a preferred embodiment of the invention, which is designed to drive a vehicle. The drive system 100 comprises a power generator 110 and a drive battery 91, which supplies an electric motor 90 with electrical energy to drive the vehicle. The drive system 100 is preferably used in hybrid vehicles, such as a passenger car, truck, bus, boat, and / or aircraft. Use in agricultural and / or construction machinery is also possible. Other applications for the drive system 100 are conceivable.

[0045] The power generator 110 comprises a gas turbine 30, a generator 31 mechanically coupled to the gas turbine 30, and a reformer 60. The gas turbine 30 comprises a first compressor 32 for compressing intake combustion air and a turbine 33 for driving the first compressor 32. According to Fig. 3The turbine 33 is a radial turbine. A combustion chamber 50 is arranged between the first compressor 32 and the turbine 33, which is fluidly connected to the first compressor 32 and the turbine 33. In other words, the first compressor 32 is arranged upstream of the combustion chamber 50 in a flow direction S' of the combustion air. The combustion chamber 50 serves to combust an air / fuel mixture consisting of supplied combustion air and supplied synthesis gas. The turbine 33 is arranged downstream of the combustion chamber 50 in a flow direction S" of the combusted air / fuel mixture.

[0046] The synthesis gas is generated by reformer 60, for which purpose a vaporized fuel is fed to reformer 60. Reformer 60 reforms the vaporized fuel into synthesis gas to increase the calorific value for combustion. Reformer 60 is connected to combustion chamber 50 to supply the generated synthesis gas. The synthesis gas and reformer 60 will be discussed in more detail later.

[0047] The generator 31 is connected to the gas turbine 30 in such a way that it absorbs a rotary motion during operation and converts it into electrical energy. This represents the normal operation of the generator 31. The generator 31 is electrically connected to the drive battery 91. As shown in Fig. 1 As can be seen, the drive battery 91 is connected by electrical lines to an electric motor 90 in order to supply it with electrical energy to drive the vehicle.

[0048] The generator 31 can also be operated as a motor. In other words, the generator 31 can be operated as an electric motor that drives the gas turbine 30. Pre-evaporation of the liquid fuel can be achieved by an electric evaporator 70. This is useful during a start-up phase of the gas turbine 30 in order to set the gas turbine 33 in rotation and thereby transition it to normal operation. Once this has been achieved, the generator 31 switches from motor operation to generator operation and then generates electrical energy.

[0049] The generator 31 can be directly connected to the turbine 33, specifically to a turbine shaft 27 of the turbine 33, to absorb the rotational movement of the gas turbine 30. However, it is also possible for a transmission to be interposed between the gas turbine 30 and the generator 31 to transmit the rotational speed of the turbine shaft 27. In other words, the generator 31 can be indirectly connected to the turbine shaft 27 of the turbine 33 to absorb the rotational movement.

[0050] As in Fig. 2 and 3As can be seen, the gas turbine 30 has a guide device 10 for flow guidance, which is arranged upstream of the turbine 33. The guide device 10 is arranged in the flow direction S" of the combusted air / fuel mixture between the combustion chamber 50 and the turbine 33. Specifically, the guide device 10 is arranged at an inlet of the turbine 33. The guide device 10 guides a flow of the combusted air / fuel mixture in a predetermined flow path to turbine blades 23 of the turbine 33. The guide device 10 is arranged in Fig. 2 For better illustration, it is shown in its uninstalled state. The design of the guidance system 10 will be discussed in more detail later.

[0051] According to Fig. 3The guide device 10, in particular in the installed state, is arranged between a turbine volute 21 and a turbine wheel 22 of the turbine 33. The turbine wheel 22 has the turbine blades 23 and rotates during operation in a bearing carrier 24, which is in Fig. 3 is clearly visible. The combusted air / fuel mixture flows through the turbine volute 21 to the guide device 10 and then to the turbine blades 23 of the turbine 33.

[0052] In Fig. 3Furthermore, a supply line 13 for supplying liquid or pre-evaporated fuel to the guide device 10 and a discharge line 14 for vaporized fuel are visible. The discharge line 14 connects the guide device 10 to the reformer 60. The supply line 13 is connected to an electric evaporator 70, which pre-evaporates the liquid fuel during the start-up phase of the gas turbine process. The electric evaporator 70 is arranged upstream of the guide device 10 in the fuel flow direction KS.

[0053] The guide device 10 is also connected upstream of the reformer 60. As in Fig. 1As can be seen, the guide device 10 is arranged in the fuel flow direction KS between the electric evaporator 70 and the reformer 60. During operation, in particular during normal operation and the start-up phase, the guide device 10 guides the flow of the combusted air / fuel mixture, in particular the exhaust gas, to the turbine 33 and supplies fuel to the reformer 60. The guide device 10 therefore has a first flow path for the combusted air / fuel mixture and a second flow path for fuel.

[0054] According to Fig. 2 The guide device 10 is annular and has a plurality of guide vanes 11. The guide vanes 11 are evenly distributed in the circumferential direction of the annular guide device. The guide vanes 11 are spaced apart from adjacent guide vanes 11, so that the combusted air / fuel mixture flows between the guide vanes 11 during operation.

[0055] As in Fig. 2 As can be clearly seen, the guide vanes 11 each have a passage 12. In other words, the guide vanes 11 are hollow. The passage 12 forms a flow channel for the fuel to be vaporized or for pre-vaporized fuel. The passage 12 can be formed by a slot. The passage 12 can additionally or alternatively be formed by one or more bores. Other shapes of the passage 12 are possible. In general, it is conceivable that the guide vanes 11 can alternatively have several passages 12 for the fuel to be vaporized or for pre-vaporized fuel.

[0056] The passage 12 forms a heat transfer area 15 (see Fig. 3), in which during operation a heat transfer takes place from the guide vanes 11 to the fuel flowing through. The heat transfer area 15 comprises an inner surface of the passage 12. The passage 12 runs transversely to the circumferential direction of the guide device 10 through the guide vanes 11. In other words, the passage 12 runs transversely to the flow direction S" of the burned air / fuel mixture. Or in other words, the passage 12 runs in a longitudinal direction of the guide device 10. According to Fig. 2 the guide device 10 forms a guide grid.

[0057] In this specific embodiment, methanol or a methanol / water mixture is used as the liquid fuel. This means that the vaporized fuel is vaporized methanol or a vaporized methanol / water mixture.

[0058] During normal operation, i.e., when the operating temperature of the guide device 10 is reached, the liquid fuel evaporates. This process cools the guide device 10 and thus protects it from thermal overload. The evaporated fuel is then fed through the discharge line 14 to the reformer 60.

[0059] The reformer 60 is adapted to produce a synthesis gas from the vaporized methanol or the vaporized methanol / water mixture with a calorific value that is 10 percent to 25 percent higher than the calorific value of the vaporized reactant.

[0060] For a synthesis gas produced by reformer 60 from vaporized methanol, the calorific value is 15 percent to 18 percent, particularly preferably 18 percent to 20 percent, higher than the calorific value of the vaporized methanol before reforming. The reaction equation for methanol to synthesis gas is as follows: CH 4 O → 2H 2 + CO.

[0061] For a synthesis gas produced by the reformer from a vaporized methanol / water mixture, the calorific value is 10 percent to 12 percent, preferably 12 percent to 14 percent, and particularly preferably 13 percent higher than the calorific value of the vaporized methanol / water mixture before reforming. The reaction equation for converting the methanol / water mixture to synthesis gas is as follows: CH 4 O + H 2 O → CO 2 + 3H 2 .

[0062] The water component for the methanol / water mixture can be added to the methanol before the guide device 10 or after the guide device 10.

[0063] To provide the water component, the power generator 110 may include a condensation unit for generating condensate from an exhaust gas stream of the gas turbine 30. The condensation unit (not shown) is preferably connected to the exhaust side of the gas turbine 30 and / or is arranged on the exhaust side of the gas turbine 30. Additionally, the power generator 110 may include a supply unit (not shown) for supplying the condensate to the liquid and / or vaporized fuel.

[0064] According to Fig. 4 a drive system 100 according to a further embodiment of the invention is shown, wherein only the differences to the drive system 100 according to Fig. 1 to 3 is entered into.

[0065] The power unit 110 of the drive system 100 according to Fig. 4additionally includes an exhaust gas turbocharger 20 and an air cooler 40. The exhaust gas turbocharger 20 has a second compressor 26 and a turbine 25 that drives the second compressor 26. The turbine 25 is mechanically coupled to the second compressor 26. Specifically, the second compressor 26 and the turbine 25 are connected to each other via a common shaft 28 to transmit a rotary motion.

[0066] The second compressor 26 and the air cooler 40 are arranged in the flow direction S' of the combustion air between the first compressor 32 and the combustion chamber 50. In other words, the second compressor 26 and the air cooler 40 are arranged downstream of the first compressor 32 in the flow direction S' and upstream of the combustion chamber 50. In the power unit 110 according to Fig. 4Thus, the first compressor 32 forms a first compressor stage for compressing the combustion air, and the downstream second compressor 26 forms a second compressor stage for further compressing the combustion air. Between the two compressors 32, 26, the compressed combustion air is intermediately cooled by the air cooler 40. The air cooler 40 is an air / air cooler. This means that air, for example ambient air, flows through the air cooler 40 to cool the combustion air in order to achieve heat dissipation. The power generator 110 according to Fig. 4 thus comprises a two-stage compression of the combustion air with intermediate cooling before entering the combustion chamber 50.

[0067] The turbine 25 of the exhaust gas turbocharger 20 is arranged in the flow direction S" of the burned air / fuel mixture between the guide device 10 and the turbine 33 of the gas turbine 30. In the power unit 110 according to Fig. 4the guide device 10 is provided on the turbine 25 of the exhaust gas turbocharger 20 and not, as in Fig. 1 shown, on the turbine 33 of the gas turbine 30. Nevertheless, with regard to the guide device 10 according to Fig. 4 to the description of the control device 10 according to Fig. 1 to 3 The arrangement of the guide device 10 on the turbine 25 corresponds to the arrangement of the guide device 10 on the turbine 33 according to Fig. 1 and 3 The design and function of the control device 10 according to Fig. 4 is the same as based on Fig. 1 to 3 described.

[0068] Additionally or alternatively, the guide device 10 can be arranged on the turbine 33. In other words, it is possible for the power unit 110 to have a total of two guide devices 10, wherein one of the guide devices 10 is arranged on each of the turbines 25, 33. According to Fig. 4the guide device 10 is arranged only on the turbine 25 of the exhaust gas turbocharger 20. This is in Fig. 3 clearly visible.

[0069] Fig. 5 shows a drive system 100 according to a further embodiment of the invention, in which the drive system according to Fig. 4 supplemented with a heat exchanger 80 for preheating the combustion air.

[0070] For the generator 110 according to Fig. 5 The heat exchanger 80 is arranged upstream of the combustion chamber 50. Specifically, the heat exchanger 80 is arranged in the flow direction S' of the combustion air between the second compressor 26 of the exhaust gas turbocharger 20 and the combustion chamber 50. The heat exchanger 80 is adapted to heat the compressed combustion air to an ignition temperature of the synthesis gas generated by the reformer 60.

[0071] The heat exchanger 80 is connected to the turbine 33 on the exhaust side. Furthermore, the heat exchanger 80 is connected to the second compressor 26. The combusted air / fuel mixture or the exhaust gas from the turbine 33 flows through the heat exchanger 80, thereby heating the compressed combustion air. The heat exchanger 80 thus heats the combustion air by means of thermal recuperation using the exhaust gas flowing from the turbine 33.

[0072] For the generator 110 according to Fig. 5The combustion chamber 50 is adapted to accelerate the combustion air to a speed that is higher than the flame speed of the synthesis gas to be combusted. This allows the combustion of the air / fuel mixture in the combustion chamber 50 to take place by means of flameless oxidation. This advantageously results in virtually no nitrogen oxides being produced, thus enabling improved, climate-friendly operation of the drive system 100.

[0073] Finally, it should be noted that the features of the two described embodiments are not limited to the individual embodiments, but can be freely combined with each other. List of reference symbols

[0074] 10 Guide device 11 Guide vanes 12 Passage 13 Supply line 14 Discharge line 15 Heat transfer area 20 Exhaust turbocharger 21 Turbine volute 22 Turbine wheel 23 Turbine blades 24 Bearing carrier 25 Turbine 26 Second compressor 27 Turbine shaft 28 Common shaft 30 Gas turbine 31 Generator 32 First compressor 33 Turbine 40 Air cooler 50 Combustion chamber 60 Reformer 70 Electric evaporator 80 Heat exchanger 90 Electric motor 91 Traction battery 100 Drive system 110 Power unit KS Fuel flow direction S' Flow direction of the combustion air S" Flow direction of the combusted air / fuel mixture

Claims

1. A drive system (100) for a vehicle, in particular for a hybrid vehicle, with at least one power unit (110) and with at least one drive battery (91), which are electrically coupled to one another, wherein the power unit (110) comprises: - at least one gas turbine (30), which has at least a first compressor (32) for the compressing of drawn-in combustion air, at least one turbine (33) for driving the first compressor (32), and at least one combustion chamber (50) arranged therebetween, for the combustion of an air / fuel mixture, which is fluidically connected to the first compressor (32) and to the turbine (33); - at least one reformer (60) for the reforming of a vaporized fuel, in particular of vaporized methanol, to a synthesis gas, wherein the reformer (60) is connected to the combustion chamber (50) for the supplying of the synthesis gas; and - at least one generator (31), which is mechanically coupled with the gas turbine (30) for receiving and / or introducing a rotary movement, wherein the drive battery (91) is electrically connected to the generator (31) of the power unit (110) and is adapted to supply with electrical energy at least one electric motor (90) for driving the vehicle and / or the generator (31), characterized in that the gas turbine (30) comprises at least one guiding device (10) for guiding the flow of the combusted air / fuel mixture, which is arranged in flow direction (S") between the combustion chamber (50) and the turbine (33), wherein the guiding device (10) is arranged upstream of the reformer (60) in a fuel flow direction (KS) and is adapted to receive, in operation, heat from the combusted air / fuel mixture and to vaporize a liquid fuel, in particular liquid methanol, through heat transfer.

2. The drive system (100) according to Claim 1, characterized in that the guiding device (10) has a plurality of guide blades (11) with respectively at least one passage (12) which is connected to a feed line (13) for liquid and / or pre-vaporized fuel, and to a discharge line (14) for vaporized fuel, wherein the passage (12) forms a heat transfer zone (15) for vaporizing the liquid fuel.

3. The drive system (100) according to any one of the preceding claims, characterized in that the reformer (60) is adapted to generate from the vaporized fuel, in particular from the vaporized methanol, a synthesis gas with a heating value which is 10 percent to 25 percent, in particular 13 percent to 20 percent, higher than a heating value of the vaporized fuel.

4. The drive system (100) according to any one of the preceding claims, characterized in that the power unit (110) has at least one condensation unit for generating condensate from an exhaust gas flow of the gas turbine (30), which is connected to the gas turbine (30) on the exhaust gas side or is arranged on the gas turbine (30), and the power unit (110) has at least one feed unit for feeding the condensate to the liquid and / or vaporized fuel.

5. The drive system (100) according to any one of the preceding claims, characterized in that the power unit (110) has at least one electric vaporizer (70) for vaporizing the liquid fuel, in particular in the start phase of the power unit (110), which is arranged upstream of the guiding device (10) in the fuel flow direction (KS).

6. The drive system (100) according to any one of the preceding claims, characterized in that the power unit (110) has at least a second compressor (26), in particular an exhaust gas turbocharger (20), and at least one air cooler (40), which are arranged in flow direction (S') of the combustion air between the first compressor (32) and the combustion chamber (50), wherein the air cooler (40) is arranged upstream of the second compressor (26).

7. The drive system (100) according to any one of the preceding claims, in particular according to Claim 6, characterized in that the power unit (110) has at least one heat exchanger (80), in particular exhaust gas heat exchanger, for the pre-heating of compressed combustion air, which is arranged between the / a second compressor (26) and / or the first compressor (32) and the combustion chamber (50), wherein the heat exchanger (80) is connected to the gas turbine (30) on the exhaust gas side for heat transfer.

8. The drive system (100) according to any one of the preceding claims, characterized in that at least one electric motor (90) is provided for driving the vehicle, in particular hybrid vehicle, which is connected to the drive battery (91).

9. A method for operating a drive system (100), in particular according to one of the preceding claims, which has at least one power unit (110) with at least one gas turbine (30), at least one reformer (60) and at least one generator (31), and at least one drive battery (91) electrically connected to the power unit (110), wherein the method comprises the following steps: - drawing in of combustion air through at least a first compressor (32) of the gas turbine (30) and compressing of the combustion air; - feeding of the compressed combustion air to a combustion chamber (50) which is arranged between the first compressor (32) and a turbine (33) of the gas turbine (30); - vaporizing of a liquid fuel, in particular of liquid methanol, through at least one guiding device (10) which, in operation, receives heat from a combusted air / fuel mixture from the combustion chamber (50) and transfers it to the through-flowing fuel; - feeding of the vaporized fuel to the reformer (60), which converts the vaporized fuel into a synthesis gas and feeds the latter to the combustion chamber (50); - combusting of the air / fuel mixture in the combustion chamber (50) and driving of the turbine (33) of the gas turbine (30); - transferring of a rotary movement from the gas turbine (30) to the generator (31) for the generating of electrical energy; and - storing of the electrical energy in the drive battery (91), which is electrically connected to the generator (31), in order to supply at least one electric motor (90) and / or the generator (31) with electrical energy.

10. The method according to Claim 9, characterized in that the compressed combustion air, before the feeding to the combustion chamber (50), is further compressed by at least a second compressor (26), in particular an exhaust gas turbocharger (20), of the power unit (110), wherein before the further compressing, the combustion air is cooled by at least one air cooler (40), which is arranged between the first compressor (32) and the second compressor (26) in flow direction (S') of the combustion air.

11. The method according to Claim 9 or 10, characterized in that the drive system comprises a heat exchanger (80), which heats the compressed combustion air at least to an ignition temperature of the synthesis gas generated by the reformer (60).

12. The method according to one of Claims 9 to 11, characterized in that the combustion chamber (50) accelerates the combustion air to a speed which is higher than a flame speed of the synthesis gas which is to be combusted.

13. A vehicle, in particular a hybrid vehicle, with at least one drive system (100) according to one of Claims 1 to 8 and at least one electric motor (90), which is connected to the drive battery (91) of the drive system (100) for driving the vehicle.

14. A use of at least one drive system (100) according to one of Claims 1 to 8 in a vehicle, in particular a passenger vehicle and / or a lorry and / or a bus, an aircraft and / or a boat, wherein the power unit (110) generates electrical energy, and the drive battery (91) stores the electrical energy, wherein the drive battery (91) is connected to at least one electric motor (90) for driving the vehicle.