DE10139617A1 - Drive arrangement, especially for vehicle, has internal combustion engine and electrical current generator(s) with fuel cell and fuel reforming system with connection(s) to engine - Google Patents

Abstract

The arrangement has an internal combustion engine (1) and an electrical current generator with a fuel cell (14) and a fuel reforming system (19) for the fuel cell. At least one connection is provided from the fuel reforming system to the engine and a controller controls the flow of a material or mixture from the reforming system into the engine.

Description

State of the art

The invention relates to a drive device with a Internal combustion engine according to the preamble of claim 1.

Vehicle drives in which a fuel cell for Generation of electrical energy in connection with one or several electric motors are used in particular in connection with the so-called zero-emission vehicle known. Such vehicles are used in part a hydrogen tank in order to operate the Provide fuel cell required fuel. In other embodiments, a system for Fuel reforming provided in the more conventional Fuel, usually in the form of hydrocarbons is present, is chemically split, the for the Operation of the fuel cell generates the required hydrogen becomes.

The vast majority of motor vehicles, however, will as before driven by reciprocating engines, which also with  provided a generator in the form of an alternator are used to power electrical peripherals supply.

However, modern motor vehicles are becoming increasingly involved a variety of consumers equipped to Additional functions to improve the engine control of the To offer comfort and security. It follows from this an increased electrical energy requirement.

Furthermore, it is in vehicles with conventional Internal combustion engine disadvantageous that the alternator only is in operation with the internal combustion engine running.

Energy consumers, such as air conditioners, blowers, pumps, etc., which is too great a burden on the motor vehicle battery can therefore only display while the Internal combustion engine can be used.

In addition, particularly in the motor vehicle sector all to fulfill safety-related functions, such as for example braking, steering or suspension, but also in other areas including engine optimization, such as z. B. for valve control, etc., electrically operated systems by. These systems often become completely electric operated and electronically by means of a control unit regulated. When supplying this additional electrical Consumers whose additional power requirements are approx. 5 to 10 kW can be conventional electrical Storage units, among other things, due to their low specific energy content can only be used to a limited extent.

In addition, the efficiency is physically in the Electricity generation through the combination of an internal combustion engine significantly restricted with an alternator.  

Advantages of the invention

The object of the invention is, in contrast Propose a drive device with an internal combustion engine which is always on even when the combustion engine is at a standstill high amount of electrical energy is available and at the same time a high efficiency in the generation of electrical energy is guaranteed.

This task is based on a device of type mentioned in the introduction by the characteristic features of claim 1 solved.

By the measures mentioned in the subclaims advantageous embodiments and developments of the invention possible.

Accordingly, one according to the invention is distinguished Drive device characterized in that both a Internal combustion engine and a fuel cell provided is.

Because the fuel cell is independent of the internal combustion engine works, is also one of the internal combustion engine Independent operation of all additional electrical components possible. For example, in a motor vehicle with the internal combustion engine switched off The air conditioning system remains switched on.

In addition, the fuel cell can in particular also an operation of the above all, safety-relevant components and functions of a land, water or aircraft. This motor independent electrical supply, for example, a corresponding electrical system especially for safety-related, electrical  controlled systems advantageous.

Preferably, the security-relevant Functions are guaranteed, even if due to a Malfunction of the internal combustion engine and / or one corresponding, generally existing electrical Storage unit, such as a vehicle battery or a vehicle accumulator, these are disturbed or fail. A corresponding electrical emergency supply using the fuel cell is particularly advantageous, z. B. when the engine is suspended, one too strong discharge of the electrical storage unit possibly due to comparatively long downtimes, during the starting phase of the internal combustion engine, etc. With This measure includes additional relatively heavy electrical storage units can be dispensed with, whereby a possibly higher fuel consumption of the Vehicle can be minimized.

Due to the independent discharge of the electrical Storage unit, even without load, can possibly be the Energy requirements of the safety-relevant components, e.g. B. from Steering, braking and / or suspension without the fuel cell not covered according to the invention shortly after the start. Here, the necessary state of charge of the electrical Storage unit with those in operation Internal combustion engine can only be reached before that Vehicle sets in motion, which is too long Waiting times could result. By means of the fuel cell especially the electrical storage unit regardless of Internal combustion engine so that the safety-relevant components right from the start are operational and thereby disadvantageous waiting times can be reduced or eliminated.

The drive device according to the invention is preferred in  Motor vehicles used, but especially in In the case of the further training described below also a Use in stationary systems that are independent of the power grid would be conceivable.

In a development of the invention, a system for Fuel reforming provided for the fuel cell. In this way, the usually for vehicles with Internal combustion engine also used fuel for the Operation of the fuel cell are used, being in one Fuel reformer the fuel for the fuel cell is produced. The fuel for the fuel cell is there for those that can be used sensibly from today's perspective Hydrogen fuel cells.

In a further particularly advantageous embodiment of the Invention is a connection between the system for Fuel reforming and the internal combustion engine provided. In this way, the internal combustion engine can in certain Operating phases as an intermediate or end product of the system Fluid present for fuel reforming become. This can, for example, be pure Hydrogen or with a hydrogen mixture additional material components, for example a CO content act. The addition can, for example, via the Fuel supply, the charge air or in the case of a Carburetor engine in the combustion mixture of the Internal combustion engine take place. By adding doses of Hydrogen, possibly in combination with CO, can Behavior of the internal combustion engine at certain Operating conditions can be meaningfully improved.

For example, the cold start behavior can be influenced in favor of lower pollutant emissions. If an exhaust gas recirculation is provided, the exhaust gas recirculation rates can be increased by adding hydrogen, which is associated with a greater NO _x reduction. Thanks to the excellent ignition behavior of hydrogen, it is also possible to lower the engine idling speed.

In addition to the three examples listed Possible uses of the hydrogen supply with and without CO enrichment from the fuel reforming plant for the fuel cell to the internal combustion engine are without further also other possible uses. Generally formulated with the possibility of Hydrogen supply is another parameter for the control of the internal combustion engine.

For the addition of the intermediate or end products from the Fuel reforming in the internal combustion engine preferably a control unit is provided which controls the dosage the addition depending on the operating state of the Internal combustion engine controls, so the possibilities for Improve the behavior of the internal combustion engine fully can be exhausted.

In a further extremely advantageous embodiment of the invention, at least one connection is made from the fuel reforming system to at least one catalytic converter for the exhaust gas purification of the internal combustion engine. This also has a number of advantages. For example, during a cold start, the catalyst can be warmed up more quickly by adding hydrogen or a hydrogen mixture. In addition, for example, the regeneration of a NO _x storage catalytic converter by adding hydrogen or a hydrogen mixture would be conceivable.

Furthermore, the addition of the Intermediate or end products from fuel reforming one or more catalysts for exhaust gas treatment of the Internal combustion engine provided a control unit which  Dosage of the addition depends on the operating state of the controls each catalyst, so the possibilities to control the operation or regeneration of a such catalyst can be fully exploited.

Because even in a fuel cell the available one Fuel is not fully implemented in a further special embodiment of the invention additionally a turbine and / or a burner, in particular a catalytically active burner to take advantage of the Residual amounts of fuel, i. H. in the case mentioned above Hydrogen, provided. In this way the Efficiency of the overall system further improved.

Such a turbine can in turn be used in different ways be used. For example, the use of the turbine possible for charge air compression of the internal combustion engine, d. H. the turbine can be used directly as a turbocharger drive become. There is also a possibility of energetic Use of this turbine in that it is a power generator is operated, the available electrical Performance of the overall system and thus its efficiency elevated.

Basically, in an advantageous manner combination of an internal combustion engine according to the invention a fuel cell like all additional components Compression units are driven by an electric motor. This offers the particular advantage that the Compression units and the resulting pressures, for example the charge air of the internal combustion engine, can be controlled independently of the speed.

Due to the possibility of electrical control of all Motor peripheral devices therefore result in more Control parameters for the operation of the internal combustion engine.  

This is an increase in engine power, for example and / or an improvement in exhaust gas emissions conventional internal combustion engines conceivable, in particular during a cold start phase of the internal combustion engine. Also the change in engine characteristics is due to such Measures possible. Accordingly, this can comparatively high environmental requirements of corresponding systems or vehicles are met.

In a further special embodiment of the invention is also at least one compression unit within the Plant used for fuel reforming. Hereby the fuel cell on the cathode and / or anode side with a relatively high pressure to be applied to the To increase the power density of the fuel cell. in this connection are preferably the starting materials of the fuel cell such as Air, water and / or fuel or intermediate and / or products of the fuel reforming by means of a or more compression units to an advantageously high Pressure level compressed. Basically, both liquid as well as vaporized or gaseous fuels and / or Water or steam can be used.

Such compression can, for example, and / or the output side of the system or the input side of the Fuel cell can be made. The compression can however also in a previous process stage or Intermediate stage of the reform can be made so that the respective material flow, d. H. the educts or Intermediates, the plant for fuel reforming with a corresponding pressure is applied. For one, can this affects the fuel reforming to another stands in the event of a connection to Internal combustion engine the intermediate or End product from fuel reforming already included increased pressure available so that the addition in the  Internal combustion engine is simplified or optimized.

At least one memory is advantageously used for Storage of an intermediate or end product of Plant and / or a substance or mixture of substances from the Fuel cell provided. With the help of an appropriate Memory is preferably staggered in time Storage and delivery of corresponding products, substances or Mixtures of substances possible. This can be possible Surpluses, for example during a partial load phase of the Fuel cell or the like, and / or defects, for example during a start or fault phase Component, these products, substances or mixtures of substances in the corresponding operating phases are balanced.

In a special variant of the invention is the memory for storing one in the internal combustion engine or the Fuel cell to be supplied substance or mixture of substances educated. This preferred design of the memory enables, for example, in a cold start or Fault phase of the internal combustion engine, the system for Fuel reforming and / or the fuel cell especially hydrogen-containing gas, especially hydrogen-rich gas Reformate, is available.

If necessary, preferably during a starting phase hydrogen-rich reformate from memory Internal combustion engine and / or the fuel cell supplied until the system is its or the internal combustion engine has reached the specified operating temperature. Mainly by the addition of previously stored hydrogen-rich gas can the cold start behavior of the internal combustion engine in such a way improve that much less pollutants in the Cold start phase can be emitted. This leads to a significant reduction of environmentally relevant substances and thus to Meeting relatively high environmental standards.  

In an advantageous variant of the invention, at least an additional power generator to supply at least safety-relevant operating units during a Start phase and / or a special operating case provided is. As already mentioned above, this measure increases hinted at the corresponding security Drive devices or vehicles, as these are increasing Dimensions electrically operated and / or electronically controlled safety-relevant operating units such as brakes, steering or the like. Accordingly, the additional power generators ensure safe operation of this Operating units, even in the event of a fault or a Failure of existing components such as alternator, Battery or the like.

Preferably the fuel cell is the additional one Power generator trained. This will at high Safety level of construction effort essential reduced. At the same time, the use of Accumulators or the like as an additional power generator Weight saved, which is particularly a problem in vehicles Improves fuel economy.

The invention relates to both process variants in which the water supplied to the process via the tank as additional fuel has to be refueled (water balance not closed), as well as variants where enough Water is condensed out behind the fuel cell Avoid refueling with water (water balance closed).

embodiment

An embodiment of the invention is in the drawing shown and will be explained in more detail below with reference to the figures  explained.

Show in detail

Fig. 1 is a schematic diagram of a combination of combustion engine and fuel cell with fuel reforming,

FIG. 2 shows a representation according to FIG. 1 of a further embodiment of the invention and

Fig. 3 is a schematic diagram for illustrating the catalyst regeneration in a vehicle according to the invention.

Fig. 1 shows the diagram at the bottom of a reciprocating engine 1 with indicated cylinders 2. Fuel 4 is supplied to the reciprocating piston engine 1 from a tank 3 . Outside air 5 is supplied to the reciprocating piston engine 1 via an engine compressor 6 . The outside air 5 can alternatively be pre-compressed via an exhaust gas turbocharger 7 . The exhaust gas 8 is aftertreated by an exhaust gas catalytic converter 9 and then released into the environment. This diagram therefore describes the functional principle corresponding to a conventional supercharged internal combustion engine. In addition, it should be mentioned at this point that the combination according to the invention can also be used, in deviation from this exemplary embodiment, in non-supercharged internal combustion engines.

Deviating from the conventional functional principle, four addition points 10 to 13 are shown here, at which an intermediate or end product of the fuel reforming system described below can be added.

The electrical energy for the periphery of the reciprocating piston engine 1 and for other electrical components, for. B. a vehicle driven thereby, is generated in the present case by a fuel cell 14 . The fuel cell 14 is schematically divided into the cathode area 15 and the anode area 16 . The fuel cell 14 is supplied with fuel in the form of a relatively hydrogen-rich reformate 17 and oxygen or outside air 18 . The hydrogen-containing reformate 17 serving as fuel is generated in a system 19 for fuel reforming. The fuel 20 is carried in a tank 21 which, under certain circumstances, can be identical to the tank 3 for the reciprocating piston engine 1 . If necessary, water 22 is still provided from a water tank 23 . As already indicated above, water can also be obtained by condensation from the reaction product of the fuel cell (not shown in more detail).

The outside air for the operation of the fuel cell 14 is compressed and conveyed via a compressor 24 .

If necessary, a preheating stage 26 can be provided for one or more starting materials supplied to the fuel cell 14 or the system for fuel reforming 19 , ie the fuel 20 , the water 22 and / or the air 27 , which preferably uses the residual anode energy. Advantageously, viewed in the direction of flow after the preheating stage 26 , the air 27 is supplied to a plurality of components via a branch 28 .

Two heat exchangers 29 , 30 are initially used for further, optional heating, in particular of all starting materials for fuel reforming, ie the fuel 20 , the water 22 and the air 27 . These starting materials 20 , 22 , 27 are then fed to a so-called reformer 31 . There, the fuel is converted into a hydrogen and carbon monoxide-containing synthesis gas 25 in an exothermic reaction using a catalyst material in the present exemplary embodiment. Process variants are also conceivable in which the addition of water to the reformer 31 can be dispensed with.

After cooling in the heat exchanger 30, the synthesis gas 25 containing hydrogen and carbon monoxide is further treated in two so-called shift stages 32 , 33 , with a large part of the carbon monoxide present in the synthesis gas 25 in a so-called shift reaction, preferably with the aid of additionally supplied water 22 , is converted to carbon dioxide and other hydrogen. Different shift stages 32 , 33 can work at different temperature levels. During the shift reaction, heat is released again, which is also used in the heat exchanger 29 for preheating fuel 20 , water 22 and air 27 , as already mentioned above.

The fuel cells currently available, in particular polymer electrolyte membrane fuel cells (PBMFC), are very sensitive to so-called carbon monoxide poisoning on the anode side. A further carbon monoxide fine cleaning stage 34 is therefore often used. This fine cleaning stage 34 may be unnecessary in future fuel cells 14 or when using solid oxide fuel cells (SOFC), since these are largely insensitive to carbon monoxide in the reformate gas or will possibly be.

SOFC fuel cells preferably have ceramic membranes with a comparatively high working temperature, so that in general a heating unit (not shown in more detail) is to be provided for heating the fuel cell 14 to the working temperature.

The hydrogen-containing starting product of the system 19 , that is to say the reformate 17 , enters the fuel cell and is largely converted into water there with the oxygen or air 18 which is fed to the cathode region 15 . This process releases electrical energy which can be used according to the invention.

However, a certain residual amount of hydrogen leaves the anode region 16 without carrying out the above-mentioned reaction. A residual amount of oxygen is also contained in the cathode exhaust gas after exiting from the cathode region 15 . After the combination, the residual hydrogen 35 and the residual oxygen 36 result in a detonating gas mixture 37 , which can be used further energetically in a burner 38 and / or a turbine 39 . The waste heat from the burner 38 or the turbine exhaust gas 40 can be used in the preheating stage 26 for preheating starting materials 20 , 22 , 27 , as is indicated by a dashed double arrow.

According to the invention, three removal points 41 , 42 , 43 are provided, for example, during the material flow in the system 19 for reforming the fuel, at which an intermediate product, for. B. the synthesis gas 25 , the reformate 17 consisting of almost pure hydrogen, or else the exhaust gas containing residual hydrogen 35 from the anode region 16 via compressors 44 , 45 , 46 and optionally via intermediate storage 47 , 48 , 49 for addition to the reciprocating piston engine 1 and / or or is provided to the exhaust gas catalytic converter 9 . These substances can be added, for example, at the addition points 10 , 11 , 12 , 13 .

In the present exemplary embodiment, the fuel cell is operated under excess pressure, which is provided via the compressor 24 . Water and fuel can be brought to the necessary pressure level in liquid, vaporized or gaseous form by means of pumps (not shown).

FIG. 2 schematically represents a further embodiment variant, ie an alternative system 19 'for fuel reforming. This is the so-called steam reforming. The addition of air to the reformer 31 and thus an exothermic partial oxidation are dispensed with. In such a system, endothermic steam reforming must take place in the reformer 31 ', for which purpose heat is coupled into the reformer 31 ' via a burner 50 . In this burner 50 , for example, the residual anode gas and, if necessary, additional fuel 20 can be converted.

The main advantages of this variant are the higher hydrogen concentration in the reformate 17 and the possibility of operating the system 19 'for generating reformate at high system pressures without any significant compression work being necessary, since the compression work of liquids, ie water 22 and fuel 20 in the liquid phase , can be implemented with little effort by means of a pump or pumps (not shown). These pumps or pumps generate the higher operating pressure of the fuel reforming to increase the power density of the fuel cell 14 and can also be used to apply a relatively high pressure to the intermediate products or products of the fuel reforming for storage or removal.

This would be a possibility in which the compressors 44 and 45 at the removal points 41 and 42 are omitted or can be replaced by comparatively simple check valves 51 and 52 . For this variant, a cycle operation in the material flow would make sense in order to decouple the pressure for removal or in the material flow of the shift stages 32 ', 33 ' of the fine cleaning stage 34 and the anode region 16 .

For this purpose, in the illustration according to FIG. 2, changeover valves 51 , 52 are arranged, which intermittently switch the material flow either for removal (removal or storage cycle) with a very high overpressure, e.g. B. about 100 bar, or for the subsequent cleaning stage (shift or fuel cell cycle) with a slight excess pressure, for. B. approx. 3 bar.

For example, the pumps or pump (not shown in more detail) can primarily use the fuel 20 and the water 22 in the extraction or storage cycle with the very high overpressure of approximately 100 bar and in the shift or fuel cell cycle with low overpressure of about 3 bar.

In addition to the illustrated in Fig. 1 and Fig. 2 types of interconnection for hydrogen production, other variants are conceivable, for. B. a carbon monoxide fine cleaning by methanation or through metal membranes.

The sequence of the individual components of the described Embodiments can vary depending on the design variant be different. Different components can too one or more units can be integrated. Depending on Membrane used in the fuel cell can in this Figure measures not shown for moistening the Cathode and / or anode inlet are required. As well are the corresponding components for water recovery not shown from the anode and / or cathode residual gas.

In the described embodiment, the electrical Energy from the fuel cell and the propulsion energy of the vehicle supplied by the reciprocating engine. The However, the combination of features according to the invention is not based on charged reciprocating engines limited, but is with all known internal combustion engines can be implemented.  

The compressors or compressors shown for air compression in the process diagram for the reciprocating piston engine 1 or for the operation of the fuel cell 14 can also be combined, for example the turbines for expanding the respective media. For example, the compressor 24 and the engine compressor 6 can be combined as well as the exhaust gas turbocharger 7 with the turbine 39 .

The expansion work obtained on the turbines can be used in a manner not shown in more detail via a generator in the form of the recovery of electrical energy. A mechanical coupling (shaft, belt, etc.) is also conceivable, as used for. B. is realized in the conventional exhaust gas turbocharger. Here are any combinations between all compressors, z. B. the compressors 6 , 24 conceivable, these compressors being driven by an electric motor if necessary in other embodiments. The same applies to the compressors 44 , 45 , 46 .

The availability of Reformat 17 with a high hydrogen content offers, in addition to the advantage of the availability of electrical energy independent of the engine with significantly better efficiencies compared to a power generator or an alternator, also interesting possibilities for improving the operation of the internal combustion engine. The fuel 4 for the reciprocating piston engine 1 and the fuel 20 for the system 19 for fuel reforming can be identical or different.

The gas composition at the three tapping points 41 , 42 , 43 given by way of example differs qualitatively as follows:
Withdrawal point 41 : medium hydrogen and high carbon monoxide content
Withdrawal point 42 : high hydrogen and low carbon monoxide content
Withdrawal point 43 : low hydrogen and low carbon monoxide content.

Depending on the intended use, a different arrangement and number of tapping points can also be expedient for the operation of the reciprocating piston engine 1 .

The substances removed via the removal point 41 , 42 , 43 can be used for engine operation as follows.

When the internal combustion engine is cold started, the shortest possible light-off times of the catalytic converter are advantageous, since the lion's share of the pollutants emitted (HC, CO, NO _x ) is emitted in this cold start phase, while the catalytic converter has not yet reached the minimum temperature required for the chemical conversion of the pollutants. This problem is exacerbated by the fact that, in order to avoid misfires, the reciprocating piston engines 1 are run with a rich mixture, ie with a very high proportion of fuel, during the first cold start cycles, which inevitably leads to high carbon monoxide and hydrocarbon raw emissions. This cold start behavior can now be improved as follows in advantageous embodiments of the invention.

During the critical cold start phase, the catalytic converter for exhaust gas aftertreatment is heated by adding hydrogen-containing reformate at the addition points 12 or 13 .

Deviates from the illustrated embodiment This process also applies to several catalytic converters  applicable. Any additional air that is required can be supplied via a Air blowers (not shown in detail) are metered. This effective heating measure is due to the extremely low Ignition temperatures of hydrogen / air mixtures Precious metal-containing catalysts, such as Exhaust gas treatment can be used.

It is also known that, in particular, admixtures of carbon monoxide cause this ignition temperature to rise sharply. However, the shift stages 32 , 33 and fine cleaning stage 34 , which are per se available for the use of a carbon monoxide-sensitive fuel cell 14 , ensure that an almost carbon monoxide-free reformate 17 is available. This can now be used advantageously for the cold start of the exhaust gas catalytic converter 9 , so that the ignition temperature is kept at the desired low level.

Furthermore, it is of particular advantage that with this method the heat input takes place in a targeted manner in the active catalyst coating of the exhaust gas catalytic converter 9 or further catalytic converters and heat losses are minimized by heating inert ballast (tube wall, catalytic converter support). If the initial temperature is not sufficient for the complete conversion of the hydrogen / air mixture, then no harmful carbon monoxide or hydrocarbon is emitted, but only harmless hydrogen. The measure described can be carried out shortly before the reciprocating piston engine is switched on, but can also overlap with the warm-up phase of the reciprocating piston engine.

In order to reduce or avoid the raw carbon monoxide and hydrocarbon emissions and the necessary mixture enrichment during the cold start phase of the reciprocating engine 1 , the reciprocating engine 1 can be supplied with (or instead of) the actual fuel 4 via the addition points 10 and / or 11 hydrogen-rich reformate become. Due to the extreme reactivity of the hydrogen, the mixture enrichment for the reciprocating piston engine 1 can be reduced or avoided entirely. Even if the hydrogen is not fully converted in the internal combustion engine, only harmless hydrogen is emitted. In extreme cases, pure hydrogen operation would be conceivable during the cold start phase with the appropriate system design (size of the buffer store, pressure, gas generation capacity, etc.).

If an exhaust gas recirculation is provided, are also advantageous further training measures possible. In the Exhaust gas recirculation is an established process to reduce raw nitrogen oxide emissions. With so-called quantity-controlled motors (throttle valve) can be controlled by the Exhaust gas recirculation also dethrottling and as a result an improvement in efficiency can be achieved.

In combustion processes with internal mixture formation, the level of the exhaust gas rate is limited by the increasing particulate emissions; in particular, exhaust gas recirculation is not possible at full load. In processes with an external mixture formation, the exhaust gas recirculation rate is limited by the fact that, with an increasing exhaust gas recirculation rate, the safe charge ignition is no longer guaranteed and the risk of misfires during operation of the reciprocating piston engine 1 increases .

Here too, exhaust gas recirculation is not possible with higher loads on the reciprocating piston engine 1 . By additionally introducing hydrogen-containing reformate 17 into the reciprocating engine, e.g. B. at the addition points 10 or 11 , due to the higher reactivity of the hydrogen compared to conventional fuels, higher exhaust gas recirculation rates and thus a greater reduction in nitrogen oxide can be realized.

Furthermore, the minimum achievable idling speed for quantity-controlled engines is currently limited, among other things, by the fact that it is not possible to throttle freely at idle, since otherwise the residual gas content in the cylinder of the reciprocating piston engine 1, which increases with increasing throttling, can lead to misfires. By adding reactive hydrogen-containing reformate 17 , e.g. B. at the addition points 10 or 11 , the risk of misfires is reduced so that the total amount of fuel (hydrogen and conventional fuel) and thus the idle speed can be reduced. In extreme cases, pure hydrogen operation is also conceivable here.

Even in the case of so-called quality-controlled engines, the idling speed is limited downwards, because excessive mixture leaning also leads to a deteriorated charge burnout or misfiring. Here too, the pre-engine addition of hydrogen-containing reformate 17 makes it possible to lower the idle speed because of the extremely wide ignition limits of hydrogen. Mixed operation as well as pure hydrogen operation are also conceivable in such engines.

By lowering the idle speed, Reciprocating engines both pollutant emissions and Reduce fuel consumption.

To purify the exhaust gas from nitrogen oxides, NO _x storage catalysts are currently preferably used. The exhaust gas is first passed through an oxidation catalytic converter in which the existing nitrogen monoxide is converted into nitrogen dioxide. This is stored as nitrate in a subsequent storage component (e.g. containing barium oxide). The storage catalytic converter must be regenerated periodically after a loading phase. So far, a rich reducing atmosphere has been generated for the regeneration of the catalyst, so that the nitrogen oxide stored as nitrate is released again and reduced to harmless nitrogen in a reducing atmosphere with the formation of carbon dioxide and / or water.

The generation of the fat phase is both internal engine as well as post-engine conceivable. In the Gasoline direct injection is currently the engine Variant favors. However, the fat one Combustion management still problematic because of increased Particle and hydrocarbon emissions occur. By pre-motoric addition of highly reactive, hydrogen-containing These emissions can also be reduced in the reformate In extreme cases, pure hydrogen operation is also conceivable is.

With the diesel engine, the internal engine generation of Fat phases compared to direct petrol injection of even higher particle and hydrocarbon emissions even more problematic. The problems mentioned can be solved by the pre-motoric addition of hydrogen-containing reformate here also at least defused if not avoided.

Because of the problems mentioned for the diesel engine too the post-motor generation of fat phases is discussed. Here too, the post-motoric addition of Hydrogen-containing reformate benefits in regeneration result.

The high reactivity of the hydrogen would be advantageous in the regeneration in full flow, since the expected shortened reaction times can reduce the additional fuel consumption which is generated indirectly by the fuel consumption for the H ₂ production by the reforming. The increased reactivity of the hydrogen-containing reformate would thus also be advantageous when used for the regeneration of the storage catalyst in a tandem system according to FIG. 3.

In FIG. 3, two storage catalytic converters 53 , 54 are arranged for the reciprocating piston engine 1 with the interposition of a changeover valve 55 . With the help of the changeover valve 55 , the storage catalytic converters 53 , 54 can be switched on alternately into the flow of the exhaust gas 8 or one of the extraction points 41 , 42 , 43 for hydrogen-containing synthesis gas 25 or reformate 17 . The storage catalytic converter located in the exhaust gas stream, ie the storage catalytic converter 54 in the switching state shown, is used for exhaust gas purification and is loaded with nitrogen oxides, while the storage catalytic converter connected to an extraction point 41 , 42 , 43 , ie the storage catalytic converter 53 is regenerated in the switching state shown. Periodic switching with the aid of the switching valve 55 thus ensures that the exhaust gas 8 of nitrogen oxides is continuously de-riched. This arrangement can easily be used in combination with further catalytic converter units for exhaust gas purification.

Since the reformate 17 provides a highly reactive reducing agent for storage regeneration, rapid catalyst regeneration is possible even with small reformate throughputs. This leads to a reduction in the indirect fuel consumption generated by the provision of the reformate.

Any combination of the above and post-motor measures conceivable.

The invention is not limited to the connection of the material flows between the system 19 for fuel reforming and the components for operating the reciprocating piston engine 1 or its exhaust gas aftertreatment.

The main advantage of the invention is to combine a fuel cell 14 with an internal combustion engine, e.g. B. a reciprocating engine 1 to provide high electrical power at high efficiencies regardless of the operation of the internal combustion engine. In a vehicle with a drive device according to the invention, electrical energy with high efficiency and the lowest pollutant emissions can therefore be provided for the operation of auxiliary units or the charging of a battery even when the internal combustion engine is switched off. In addition, the buffers 47 , 48 , 49 can also be filled when the internal combustion engine is at a standstill.

Thanks to the electrical energy available independently of the motor come new opportunities in the electrification of Auxiliary units in question. For example, a Parking air conditioning by electrically powered Climate components can be realized. The use of electrically driven high pressure pumps, for example in Common rail or so-called pump-nozzle units in favor of needs-based and efficiency-optimized Operation possible.

Further systems to be supplied with electricity from the fuel cell 14 are, for example, electrohydraulic valve operation and electrically heated catalytic converter devices. Of particular importance is the supply of safety-related systems or components of the vehicle, such as. B. electrically actuated or electronically controlled brake, steering and / or suspension.

In a special case of operation, the control unit may determine that the electrical systems are insufficiently supplied, for example if the on-board electrical system voltage is insufficient due to the insufficient state of charge of the electrical storage unit, not shown. B. the generally existing vehicle battery drops. In a corresponding case, the fuel cell 14 in particular enables this electrical storage unit to be charged. For this purpose, the corresponding operating materials 17 , 18 are supplied to the fuel cell 14 .

Alternatively, in corresponding special operating cases, a direct supply of electrical components can also be provided by means of the fuel cell 14 . Basically, the aforementioned measures with the aid of the fuel cell 14 ensure the function of an emergency system for maintaining the functionality of at least the safety-relevant systems.

Furthermore, with the combination of features according to the invention the number of mechanical couplings between each Aggregates can be reduced. It's kind of a "belt-free" motor possible. This allows the installation space reduced in size and more flexible Wear of such mechanical drive couplings eliminated.

In addition, the above results Possibilities in advantageous developments of the invention innovative combustion and exhaust gas concepts for improvement the emission behavior through the availability of to implement hydrogen-containing reformate.

Claims (17)

1. Drive device, in particular for vehicles, with an internal combustion engine and an electrical power generator, characterized in that a fuel cell ( 14 ) is provided. 2. Device according to claim 1, characterized in that a system ( 19 ) for fuel reforming for the fuel cell ( 14 ) is provided. 3. Device according to one of the preceding claims, characterized in that at least one connection from the system ( 19 ) for fuel reforming to the internal combustion engine ( 1 ) is provided. 4. Device according to one of the preceding claims, characterized in that a control unit for metered control of the inflow of a substance or substance mixture from the system ( 19 ) for fuel reforming into the internal combustion engine ( 1 ) is provided. 5. Device according to one of the preceding claims, characterized in that at least one connection from the system ( 19 ) for fuel reforming to at least one exhaust gas catalytic converter ( 9 ) of the internal combustion engine ( 1 ) is provided. 6. Device according to one of the preceding claims, characterized in that a control unit for metered control of the inflow of a substance or mixture of substances from the system ( 19 ) for fuel reforming into an exhaust gas catalytic converter ( 9 ) of the internal combustion engine ( 1 ) is provided. 7. Device according to one of the preceding claims, characterized in that a turbine ( 39 ) is provided for recycling residual quantities of fuel not converted in the fuel cell ( 14 ). 8. Device according to one of the preceding claims, characterized in that a burner ( 38 ) is provided for the residual quantity utilization of fuel not converted in the fuel cell ( 14 ). 9. Device according to one of the preceding claims, characterized in that a compression of the charge air or the combustion mixture of the internal combustion engine ( 1 ) with the turbine ( 39 ) is provided. 10. Device according to one of the preceding claims, characterized in that a current generator driven by means of the turbine ( 39 ) is provided. 11. Device according to one of the preceding claims, characterized in that an electromotive compressor ( 6 ) is provided for compressing the charge air or the combustion mixture of the internal combustion engine. 12. Device according to one of the preceding claims, characterized in that at least one compressor ( 24 ) is provided for compressing a substance or mixture of substances for the operation of the fuel cell ( 14 ). 13. Device according to one of the above claims, characterized in that at least one compressor ( 44 , 45 , 46 ) is provided for compressing a substance or mixture of substances for addition into the internal combustion engine ( 1 ). 14. Device according to one of the above claims, characterized in that at least one memory ( 47 , 48 , 49 ) for storing an intermediate product ( 25 ) or end product ( 17 ) of the system ( 19 ) and / or a substance or substance mixture ( 35 ) from the fuel cell ( 14 ) is provided. 15. Device according to one of the preceding claims, characterized in that the memory ( 47 , 48 , 49 ) for storing a substance or substance mixture ( 17 , 25 , 35 ) to be fed into the internal combustion engine ( 1 ) or the fuel cell ( 14 ). is trained. 16. Device according to one of the claims mentioned, characterized characterized that at least one additional Electricity generator to supply at least safety-relevant operating units during a Start phase and / or a special operating case provided is. 17. Device according to one of the above claims, characterized in that the fuel cell ( 14 ) is designed as the additional power generator ( 14 ).