DE102016204142A1 - Method for operating an internal combustion engine device and internal combustion engine device - Google Patents

Abstract

The invention relates to a method for operating an internal combustion engine device (1), wherein a first fuel is supplied to a first combustion chamber (3) of the internal combustion engine device (1), wherein the first fuel is burned in the first combustion chamber (3) with excess air, wherein oxygen-containing combustion gas (5) from the first combustion chamber (3) is supplied to a second combustion chamber (7) of the engine device (1), wherein the combustion gas (5) is reacted in the second combustion chamber (7) in a stoichiometric combustion, and wherein exhaust gas (9) from the second combustion chamber (7) is fed to a three-way catalyst (11).

Description

Method for operating an internal combustion engine device and internal combustion engine device

The invention relates to a method for operating an internal combustion engine device and an internal combustion engine device.

In order to achieve the highest possible efficiency for an internal combustion engine, a lean combustion is often provided, wherein fuel is burned in a combustion chamber of the internal combustion engine with excess air. The disadvantage here is that the resulting in such a combustion exhaust gas on the other hand, due to the comparatively low exhaust gas temperature on the one hand and the relatively high oxygen content on the other hand difficult to post-treatment. In particular, it is not possible to convert pollutants in the exhaust gas in a comparatively simple manner in a three-way catalyst, because this for efficient operation a very narrow window for a combustion air-fuel ratio in the combustion chamber, which is also referred to as lambda value , needed. In particular unburned hydrocarbons and especially - in gas engines - chemically very stable methane in the exhaust gas can be very difficult or impossible to implement. On the other hand, although internal combustion engines which realize stoichiometric combustion have the advantage of being able to use a three-way catalytic converter for exhaust gas aftertreatment, they are inferior to lean-burn engines in terms of their efficiency.

The invention has for its object to provide a method for operating an internal combustion engine device and an internal combustion engine device, said disadvantages do not occur.

The object is achieved by providing the subject matters of the independent claims. Advantageous embodiments emerge from the subclaims.

The object is achieved in particular by providing a method for operating an internal combustion engine device in which a first fuel is supplied to a first combustion chamber of an internal combustion engine device, wherein the first fuel is burned in the first combustion chamber with excess air. Oxygen-containing combustion gas is thereby produced as the product gas of the combustion in the first combustion chamber, the oxygen-containing combustion gas being supplied from the first combustion chamber to a second combustion chamber of the internal combustion engine device, the combustion gas being converted into stoichiometric combustion in the second combustion chamber. Exhaust gas is produced as product gas of the combustion in the second combustion chamber, the exhaust gas from the second combustion chamber being fed to a three-way catalytic converter. In connection with the method, there are advantages compared to the prior art. In particular, the combustion with excess air in the first combustion chamber allows a high efficiency for the internal combustion engine device, at the same time the stoichiometric combustion in the second combustion chamber allows a cheap, simple and very efficient exhaust aftertreatment with a three-way catalyst. Particularly difficult to convert components of the combustion gas can be implemented in the stoichiometric combustion process in the second combustion chamber. In particular, the temperatures prevailing in the stoichiometric combustion in the second combustion chamber are readily high enough to efficiently and preferably fully react even chemically very stable molecules such as methane, in particular to oxidize.

The term "combustion gas" is - as already stated - from the combustion in the first combustion chamber resulting product gas, ie in particular exhaust gas of the first combustion chamber, which can also be referred to as the first exhaust gas understood. The term "exhaust gas" is here specifically understood as meaning product gas of the stoichiometric combustion in the second combustion chamber, that is to say exhaust gas of the second combustion chamber, which can also be referred to as second exhaust gas. By the term "total exhaust gas" exhaust gas of the engine device is understood, which leaves the three-way catalyst, that is present downstream of the three-way catalyst.

An internal combustion engine device is understood to mean a device which has at least one internal combustion engine. It is possible that the internal combustion engine device has more than one internal combustion engine, in particular two internal combustion engines. It is also possible that the internal combustion engine device has an internal combustion engine and a reaction chamber, in particular as a second combustion chamber, wherein only a combustion, but not a conversion of chemical energy into mechanical work can take place in the reaction chamber.

According to one embodiment of the invention it is provided that the first combustion chamber, a methane-containing fuel gas is supplied as the first fuel. In particular, the first combustion chamber natural gas can be supplied as fuel, but also CNG (compressed natural gas), LNG (Liquefied Natural Gas) or the like. Will the first Combustion chamber fed as fuel, a methane-containing fuel gas, realized in a special way, the advantages of the method, because unburned methane can be efficiently implemented in the stoichiometric combustion, which is carried out in the second combustion chamber.

The second combustion chamber is preferably supplied with a second fuel, in particular in order to enable combustion in the second combustion chamber in the first place. In this case, the quantity of the second fuel supplied to the second combustion chamber is preferably controlled or regulated, wherein in particular a lambda value for the combustion in the second combustion chamber is controlled or regulated. The lambda value in the second combustion chamber is preferably regulated in a narrow lambda window, in particular between at least 0.99 and at most 1. It is possible that the first fuel is supplied to the second combustion chamber as the second fuel, which is also supplied to the first combustion chamber. But it is also possible that the second combustion chamber, a different fuel supplied from the first fuel, for example, another gaseous fuel, or even a liquid fuel, such as gasoline, diesel, dimethyl ether, or another ignition oil.

According to one embodiment of the invention it is provided that the combustion gas is supplied to the second combustion chamber before flowing through an exhaust gas turbine. This means, in particular, that the second combustion chamber is arranged downstream of the first combustion chamber, but upstream of an exhaust gas turbine, so that the combustion gas passes into the second combustion chamber upstream of the exhaust gas turbine. Alternatively, it is possible that the combustion gas is supplied between a first exhaust gas turbine and a second exhaust gas turbine of the second combustion chamber. The second combustion chamber is arranged in this case downstream of the first exhaust gas turbine and upstream of the second exhaust gas turbine. In this way, on the one hand enthalpy of the combustion gas in the first exhaust gas turbine can be used, and on the other hand, the second combustion chamber can be supplied by the enthalpy in the first exhaust gas cooled combustion gas, which increases the filling of the second combustion chamber. Alternatively or additionally, it is possible that the combustion gas is supplied to the second combustion chamber after flowing through an exhaust gas turbine. In particular, it is possible for the combustion gas to be supplied to the second combustion chamber downstream of a last exhaust gas turbine, viewed overall along the flow path of the gas flow.

Alternatively or additionally, it is preferably provided that the exhaust gas of the second combustion chamber is supplied to an exhaust gas turbine. The exhaust gas formed as product gas of the stoichiometric combustion has a particularly high enthalpy, which can be implemented in a very favorable manner in an exhaust gas turbine.

Under an exhaust gas turbine is generally understood here a turbine which is driven by product gas combustion, so in particular by the combustion gas, the exhaust gas, or from the total exhaust gas of the internal combustion engine device. Such an exhaust gas turbine may be part of an exhaust gas turbocharger, wherein the exhaust gas turbocharger preferably has the exhaust gas turbine and a compressor, wherein the exhaust gas turbine is operatively connected to the compressor such that the compressor can be driven by the exhaust gas turbine. The compressor is preferably configured to compress combustion air, which is supplied to the first combustion chamber and / or the second combustion chamber. It is possible that the engine device has a multi-stage charge, wherein more than one exhaust gas turbocharger are provided; In particular, it is possible that the internal combustion engine device has a two-stage supercharging with a high-pressure exhaust gas turbocharger and a low-pressure exhaust gas turbocharger. In this case, an exhaust gas turbine of the low-pressure turbocharger may be driven, for example, by the exhaust gas, wherein a turbine of the high-pressure exhaust gas turbocharger may be driven, for example, by the combustion gas. But it is also possible that both the high-pressure turbine and the low-pressure turbine can be driven by the exhaust gas.

However, such an exhaust gas turbine can also be designed as a power turbine. In this case, a turbine is also understood to mean a turbine which can be driven by product gas from combustion, in this case in particular by combustion gas, exhaust gas or total exhaust gas of the internal combustion engine device. Here, the power turbine is associated with a conversion device, so that the conversion device is driven by the power turbine. The conversion device can be a torque conversion device, for example a transmission, with mechanical work of the useful turbine preferably being supplied to a shaft of the internal combustion engine device, in particular a crankshaft. However, the conversion device can also be set up as an energy conversion device, in particular as an electrical machine, particularly preferably as a generator, wherein the mechanical work of the useful turbine can preferably be converted into electrical energy. Particularly preferably, a power turbine is provided which can be driven by the exhaust gas. Alternatively or additionally, a useful turbine is preferably provided which can be driven by the total exhaust gas of the internal combustion engine device.

According to one embodiment of the invention it is provided that combustion air is supplied to the combustion gas upstream of the second combustion chamber. Particularly preferably, the combustion gas upstream of the second combustion chamber charge air, that is, compressed combustion air supplied. In this way, it is possible to enrich the combustion gas with oxygen upstream of the second combustion chamber. In this context, it should be noted that ultimately the combustion gas from the first combustion chamber in the second combustion chamber virtually fulfills the function of combustion air, because the combustion gas has oxygen. An oxygen enrichment of the combustion gas by admixing combustion air can be used for controlling and / or regulating the lambda value in the second combustion chamber. At the same time as the oxygen is the second combustion chamber with the combustion gas but also exhaust gas in the sense of combustion residues and in particular inert gases, such as carbon dioxide fed. The combustion gas, which is supplied to the second combustion chamber, thus also realizes an exhaust gas recirculation there. A lambda value of 2 is preferably set for the first combustion chamber, in which case the charge composition in the second combustion chamber - without combustion air supply to the combustion gas - corresponds to a stoichiometric combustion at lambda = 1 with an exhaust gas recirculation rate of 50%. This is already a comparatively high exhaust gas recirculation rate, which may possibly adversely affect the combustion stability in the second combustion chamber, and which in particular should not be exceeded. Particularly preferably, a lambda value of greater than 2 is set for the first combustion chamber, wherein higher lambda values in the first combustion chamber in particular increase the efficiency and at the same time reduce the exhaust gas recirculation rate for the second combustion chamber. However, lambda values of less than 2 are also possible for the first combustion chamber.

In order to keep the combustion stable in the second combustion chamber and in particular to be able to lower the exhaust gas recirculation rate - even if a lambda value of 2 is not reached in the first combustion chamber - combustion air, in particular charge air, can be supplied to the combustion gas upstream of the second combustion chamber. This allows the exhaust gas recirculation rate - preferably controlled or regulated - are lowered, which increases the combustion stability in the second combustion chamber.

In the first combustion chamber, combustion at lambda = 2 or a higher lambda value is preferably aimed at, on the one hand to keep the efficiency as high as possible and, on the other hand, to realize the lowest possible exhaust gas recirculation rate for the second combustion chamber. In this case, it should be noted that increases in exhaust fiercer combustion in the first combustion chamber, the exhaust gas recirculation rate for the second combustion chamber.

The supply of the combustion air to the combustion gas upstream of the second combustion chamber is preferably controlled or regulated. For this purpose, a correspondingly suitable valve device is preferably provided. The charge air supplied to the combustion gas upstream of the second combustion chamber is preferably branched off from a charge air line, in particular downstream of a high-pressure compressor, downstream of a low-pressure compressor and / or between a low-pressure compressor and a high-pressure compressor, or elsewhere in the charge air line.

According to one embodiment of the invention it is provided that the combustion gas is heated or cooled upstream of the second combustion chamber. This can be influenced in a favorable manner, in particular the change of charge for the combustion chambers. In particular, the exhaust backpressure level for the first combustion chamber can preferably be lowered. Additionally or alternatively, it is possible that the exhaust gas is heated or cooled upstream of the three-way catalyst and / or downstream of the three-way catalyst. In this way, the exhaust gas temperature can be adjusted in a favorable manner for the three-way catalyst and / or provided for downstream of the three-way catalyst elements, in particular controlled or regulated.

It is also possible that waste heat from the exhaust gas, and / or waste heat from the combustion gas is supplied to a waste heat recovery. In this case, in particular, a cooling device provided for the combustion gas and / or for the exhaust gas can be used in order to remove waste heat from the exhaust gas and / or the combustion gas and to supply it to a waste heat utilization. Such waste heat utilization may in particular include a thermodynamic cycle, more preferably an organic Rankine cycle (ORC - Organic Rankine Cycle).

Particularly preferably, a cooling device provided for the use of waste heat upstream of the second combustion chamber is provided in such a way that it can be charged directly with the combustion gas without an exhaust gas turbine being provided upstream of the cooling device. This has the advantage that the cooling device can be acted upon with combustion gas whose enthalpy is not reduced by an exhaust gas turbine. The combustion gas can therefore flow to the cooling device with very high temperature, so that the efficiency for the waste heat recovery is high.

According to one embodiment of the invention, it is provided that the combustion gas is compressed upstream of the second combustion chamber. This is advantageous because in this way the degree of filling of the second combustion chamber can be increased.

According to a preferred embodiment of the method it is provided that a compressor for the combustion gas is driven by a turbine, which is acted upon by the combustion gas itself. In particular, the combustion gas is first supplied to the turbine and then to the compressor, so that the turbine drives the compressor and the combustion gas is first expanded in the turbine and then compressed again in the compressor. The combustion gas is preferably cooled downstream of the turbine and upstream of the compressor. It is thus particularly preferably compressed to a lower temperature level than corresponds to the temperature level at which the combustion gas is expanded in the turbine.

But it is also possible that the compressor for the combustion gas is driven by a turbine, which is acted upon by combustion air. Particularly preferably, the turbine is charged with charge air, that is to say with compressed combustion air. In this case, the high pressure level of the charge air can be used to drive the turbine to compress the combustion gas.

It is additionally or alternatively provided that the combustion gas - in particular upstream of the compressor - by combustion air, in particular by charge air, is cooled. In this case, it is possible, in particular, for the combustion gas to be cooled by combustion air flowing to the turbine, by combustion air flowing out of the turbine, or both by combustion air flowing to the turbine and also flowing away from the turbine. Advantageously, the temperature level of the combustion air, which is typically lower than the temperature level of the combustion gas, can be used to cool the combustion gas. A diversion and / or reintroduction of charge air from and / or to a charge air line of the internal combustion engine device preferably takes place upstream of an intercooler. In this way, the absorbed by the charge air enthalpy of the combustion gas can be dissipated in the intercooler.

The object is also achieved by providing an internal combustion engine device which has a first combustion chamber, to which a first fuel can be supplied. The first fuel is combustible in the first combustor with excess air. The internal combustion engine device has a second combustion chamber, which can be fed with oxygen-containing combustion gas from the first combustion chamber. The combustion gas can be converted in the second combustion chamber in a stoichiometric combustion. The internal combustion engine device has a three-way catalytic converter to which exhaust gas can be supplied from the second combustion chamber. In connection with the internal combustion engine device, in particular, the advantages which have already been explained in connection with the method are realized. Preferably, the internal combustion engine device is set up in order to supply the first combustion chamber with a methane-containing fuel gas, in particular natural gas, CNG, LNG, or the like, as fuel.

A second fuel can preferably be supplied to the second combustion chamber, in particular to enable combustion in the second combustion chamber in the first place. In this case, the quantity of the second fuel which can be supplied to the second combustion chamber can preferably be controlled or regulated, in particular in order to control or regulate a lambda value for the combustion in the second combustion chamber. It is possible that the second fuel, the first fuel is supplied to the second combustion chamber, which is also the first combustion chamber can be fed. But it is also possible that the second combustion chamber, a different fuel from the first fuel is supplied, for example, another gaseous fuel, or even a liquid fuel, such as gasoline, diesel, dimethyl ether, or other ignition oil.

According to one embodiment of the invention, it is provided that the first combustion chamber and the second combustion chamber are assigned to different internal combustion engines. In this case, the internal combustion engine device preferably has at least two, preferably exactly two internal combustion engines, wherein the first combustion chamber is assigned to a first internal combustion engine, and wherein the second combustion chamber is assigned to a second internal combustion engine. It is possible that both the first internal combustion engine and the second internal combustion engine are designed as reciprocating engines, as rotary piston engines or in any other suitable manner. It is also possible that both internal combustion engines are designed as gas turbines. The internal combustion engines can also be designed differently. In particular, it is possible that the first internal combustion engine is designed as a reciprocating engine or rotary piston engine, wherein the second internal combustion engine is designed as a gas turbine.

According to one embodiment of the invention it is provided that the first combustion chamber and the second combustion chamber of the same internal combustion engine are assigned. In this case, the Internal combustion engine device particularly preferably exactly one internal combustion engine, which has both the first combustion chamber and the second combustion chamber.

It is possible that the first combustion chamber and the second combustion chamber are assigned to different cylinder banks of the same internal combustion engine. It is particularly possible that the internal combustion engine is designed as a reciprocating engine having a V-configuration or a W-configuration of cylinder banks, wherein the first combustion chamber of a first cylinder bank and the second combustion chamber is associated with a second cylinder bank.

However, it is alternatively or additionally also possible that the first combustion chamber is designed as a dispensing cylinder, wherein the second combustion chamber is designed as a receiver cylinder. In this case, it is possible, in particular, for both combustion chambers to be assigned to the same cylinder bank of the same internal combustion engine. Preferably, a cylinder bank has a first subset of cylinders formed as a donor cylinder, the cylinder bank having a second subset of cylinders formed as a receiver cylinder. The donor cylinders are preferably operated as first combustion chambers, wherein a lean burn with excess air is carried out in the donor cylinders. The receiver cylinders are preferably operated with stoichiometric combustion. In particular, since the donor cylinder must be throttled to obtain a sufficient pressure level for the transfer of the combustion gas into the receiver cylinder, it is advantageous if the donor cylinder are operated with a lean burn, as this can ensure increased combustion stability in the throttled donor cylinders. It is also preferred that the first subset of the donor cylinders have a smaller number of cylinders than the second subset of the recipient cylinders. This is particularly advantageous because in this way the exhaust gas recirculation rate for the receiver cylinders can be kept at a sufficiently low level. For example, it is possible that such a cylinder bank has six cylinders, two of which are operated as a donor cylinder, four cylinders are operated as a receiver cylinder.

Such an internal combustion engine is preferably designed as a reciprocating engine. It is possible that an internal combustion engine of the internal combustion engine device is arranged to drive a passenger car, a truck or a commercial vehicle. In a preferred embodiment, the internal combustion engine is used to drive in particular heavy land or water vehicles, such as mine vehicles, trains, the internal combustion engine is used in a locomotive or a railcar, or ships. It is also possible to use the internal combustion engine to drive a defense vehicle, for example a tank. An exemplary embodiment of the internal combustion engine is preferably also stationary, for example, used for stationary power supply in emergency operation, continuous load operation or peak load operation, the internal combustion engine in this case preferably drives a generator. A stationary application of the internal combustion engine for driving auxiliary equipment, such as fire pumps on oil rigs, is possible. Furthermore, an application of the internal combustion engine in the field of promoting fossil raw materials and in particular fuels, for example oil and / or gas, possible. It is also possible to use the internal combustion engine in the industrial sector or in the field of construction, for example in a construction or construction machine, for example in a crane or an excavator. The internal combustion engine is preferably designed as a diesel engine, as a gasoline engine, as a gas engine for operation with natural gas, biogas, special gas or another suitable gas. In particular, when the internal combustion engine is designed as a gas engine, it is suitable for use in a cogeneration plant for stationary power generation.

According to one embodiment of the invention, it is provided that the internal combustion engine device has a compressor device for compressing the combustion gas, wherein the compressor device comprises a compressor which can be flowed through by the combustion gas, which is in drive connection with a turbine, so that the compressor can be driven by the turbine. The turbine may be disposed in the flow path of the combustion gas upstream of the compressor. In this case, the turbine is driven by the combustion gas before it is recompressed in the compressor. Downstream of the turbine and upstream of the compressor, a cooling device for cooling the combustion gas is preferably provided.

Alternatively, it is also possible for the turbine to be arranged in a flow path which is set up as intended in order to be exposed to combustion air. In particular, the flow path is preferably set up to be charged with charge air. In this case, the turbine can be charged with - preferably compressed - combustion air. Preferably, a branch for the charge air from a charge air path downstream of a charge air compressor, in particular a high-pressure compressor, and upstream of a charge air cooler is provided. It is it is possible for the charge air to be branched off from the charge air path, fed to the turbine and returned to the charge air path downstream of the turbine. In this case, a bypass or bleed line for the charge air path is provided, with the turbine of the compressor device being arranged in the bypass path or bypass.

According to one embodiment of the invention, it is provided that upstream of the compressor of the compressor device, a cooling device for cooling the combustion gas is arranged, wherein the cooling device of - preferably compressed - combustion air can be flowed through as a cooling medium. The lower temperature level of the combustion air can thus be used to cool the combustion gas. It is possible for the cooling device to be able to flow through the combustion air as the cooling medium after it has flowed through-that is, downstream-of the turbine. As an alternative or in addition, it is also possible for the cooling device to be able to flow through the combustion air before it flows through, ie upstream, of the turbine. In particular, it is possible that the combustion air is passed through the cooling device both before flowing through and after flowing through the turbine as a cooling medium.

It is possible that between the cooling device and the compressor, a further cooling device for cooling the combustion gas is arranged, said cooling device preferably does not use combustion air as the cooling medium, but rather is penetrated by another - preferably liquid - cooling medium.

The description of the method on the one hand and the internal combustion engine device on the other hand are to be understood as complementary to each other. Method steps that have been explicitly or implicitly described in connection with the internal combustion engine device are preferably individually or combined with each other steps of a preferred embodiment of the method. Features of the engine device that have been implicitly or explicitly described in connection with the method are preferably individually or combined with each other features of a preferred embodiment of the internal combustion engine device. The method is preferably characterized by at least one method step, which is due to at least one feature of an inventive or preferred embodiment of the internal combustion engine device. The internal combustion engine device is preferably characterized by at least one feature which is caused by at least one method step of a preferred embodiment of the method according to the invention or preferred embodiment.

The invention will be explained in more detail below with reference to the drawing. Showing:

1 a schematic representation of a first embodiment of an internal combustion engine device;

2 a schematic representation of a second embodiment of an internal combustion engine device;

3 a schematic representation of a third embodiment of the internal combustion engine device;

4 a schematic representation of a fourth embodiment of the internal combustion engine device;

5 a schematic representation of a fifth embodiment of the internal combustion engine device, and

6 a schematic representation of a sixth embodiment of the internal combustion engine device.

1 shows a schematic representation of a first embodiment of an internal combustion engine device 1 , The engine device 1 has a first combustion chamber, here six first combustion chambers, of which the sake of clarity, only a first combustion chamber 3 is provided with a reference numeral. The first combustion chamber 3 is a first fuel, preferably a methane-containing fuel gas fed. This first fuel is in the first combustion chamber 3 combustible with excess air. In the first combustion chamber 3 Thus, in particular, a lean burn process is realized. In this case, oxygen-containing combustion gas 5 formed, which a second combustion chamber, here six second combustion chambers, of which the sake of clarity, only a second combustion chamber 7 is provided with a reference numeral, can be fed. The combustion gas 5 is in the second combustion chamber 7 stoichiometrically feasible. In the second combustion chamber is thus in particular a combustion at a lambda value of 1 carried out. exhaust 9 from the second combustion chamber is a three-way catalyst 11 fed. The engine device 1 thus has in particular the first combustion chamber 3 , the second combustion chamber 7 and the three-way catalyst 11 on.

It is possible that the first combustion chamber 3 associated with a first internal combustion engine, wherein the second combustion chamber 7 associated with a second internal combustion engine. But it is also possible that the first combustion chamber 3 a first cylinder bank 13 is assigned, wherein the second combustion chamber 7 a second cylinder bank 15 the same internal combustion engine 17 is assigned, wherein the internal combustion engine 17 can be designed in particular as a V-engine or as a W-motor. In the embodiment of the internal combustion engine device shown here 1 has the engine device 1 exactly the one internal combustion engine 17 with two cylinder banks, namely the first cylinder bank 13 and the second cylinder bank 15 on, the internal combustion engine 17 is designed as a V-engine.

The first combustion chamber 3 is combustion air 19 along a loading path 21 can be fed, in which case a first exhaust gas turbocharger 23 is provided in the charging path 21 a first compressor 25 for compressing the combustion air 19 having, wherein the compressed combustion air 19 Also referred to as charge air. Downstream of the first compressor 25 is a first intercooler 27 in the loading path 21 arranged.

The first fuel is the first combustion chamber 3 can be fed in different ways:
For example, it is possible for a direct injection into the first combustion chamber 3 is provided. But it is also possible that along the charging path 21 a carburetor or gas mixer is provided, or that a single-point or multi-point injection is provided.

Also the second combustion chamber 7 Preferably, a fuel is supplied, which may be identical to the first fuel, but which may also be another, in particular a liquid fuel. It is also with respect to the second combustion chamber 7 possible that a direct injection, a multi-point injection or a single-point injection is provided. In principle, it is also possible to provide a carburetor or gas mixer, which then the fuel directly with the combustion gas 5 mixed. The second fuel becomes the second combustion chamber 7 in particular controlled or regulated supplied in such a way that in the second combustion chamber 7 a stoichiometric combustion at a lambda value of 1 takes place. In this case, regulation preferably takes place on a very narrow lambda window, in particular of at least 0.99 or at most 1 ,

In the embodiment shown here is a first cooling device 29 downstream of the first combustion chamber 3 and upstream of the second combustion chamber 7 in the flow path of the combustion gas 5 provided, wherein the combustion gas 5 by means of the first cooling device 29 is coolable. This allows the second combustion chamber 7 cooled combustion gas 5 be supplied, which in particular affects the charge exchange advantageous. In particular, the exhaust backpressure level for the first combustion chamber can preferably be lowered.

The exhaust 9 is along an exhaust path 31 a first exhaust gas turbine 33 fed. The first exhaust gas turbine 33 can basically be designed as a power turbine. In the concrete embodiment according to 1 However, it is part of the first exhaust gas turbocharger 23 and in particular with the first compressor 25 driveabgetrunden, so that the first compressor 25 through the first exhaust gas turbine 23 is drivable. The exhaust 9 becomes the first exhaust gas turbine 33 in particular upstream of the three-way catalyst 11 fed. Alternatively, it is also possible that the three-way catalyst 11 upstream of the first exhaust gas turbine 33 is arranged. It is also possible that a bypass path, not shown here, in particular a bypass, around the first exhaust gas turbine 33 is provided, in particular at a cold start the three-way catalyst 11 To be able to supply exhaust gas at a higher temperature in order to heat it up to operating temperature more quickly.

It turns out that in the first combustion chamber 3 a lean gas combustion can be carried out with high efficiency. Resulting pollutants, especially unburned hydrocarbons and especially chemically stable, unburned methane, can in the course of stoichiometric combustion in the second combustion chamber 7 be implemented. The stoichiometric combustion in the second combustion chamber 7 in turn allows a simple aftertreatment of the exhaust gas 9 with the three-way catalyst 11 , In particular, the hydrocarbon emissions of the first combustion chamber 3 put into action, and the subsequent three-way catalyst 11 allows a technically simple implementation of nitrogen oxide, carbon monoxide and hydrocarbon emissions from the second combustion chamber 7 ,

Will the first combustion chamber 3 powered by diesel fuel, the second combustion chamber affects 7 reducing on particulate emissions, since in the first combustion chamber 3 in lean operation resulting particles in the stoichiometric and especially homogeneous combustion process of the second combustion chamber 7 be implemented. The three-way catalyst 11 then converts the gaseous emissions.

Thus, the higher efficiency by the consumption-optimized lean burn gas in the first combustion chamber 3 combined with that for the reaction in the three-way catalyst 11 suitable, stoichiometric combustion in the second combustion chamber 7 , which results in lowest emissions. In addition, a can also Selective catalytic conversion of nitrogen oxides can be saved, which brings cost advantages. The thermal load of the components is generally lower than in a conventional gasoline engine with stoichiometric combustion. Incidentally, for the second combustion chamber 7 in a very simple manner, a high-pressure exhaust gas recirculation by the supply of the combustion gas 5 realized, can be dispensed with external compressors for increasing the pressure of the recirculated exhaust gas.

2 shows a schematic representation of a second embodiment of the internal combustion engine device 1 , Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. Here it is clear that in the second embodiment of the internal combustion engine device 1 according to 2 a two-stage supercharging is provided, in addition to the first exhaust gas turbocharger 23 , which is provided here as a low-pressure exhaust gas turbocharger, also a second exhaust gas turbocharger 35 is provided, which is set up as a high-pressure exhaust gas turbocharger. This has a second compressor 37 as well as a drive-connected, second exhaust gas turbine 39 on. Here is the combustion gas 5 from the first combustion chamber 3 upstream of the second combustion chamber 7 the second exhaust gas turbine 39 can be fed to their drive.

In the loading path 21 is downstream of the second compressor 37 a second intercooler 41 arranged.

It should be noted that it is also possible in principle in the embodiment according to 1 to provide a two-stage charge.

The second embodiment according to 2 also differs from the first embodiment according to 1 , as here the first combustion chamber 3 and the second combustion chamber 7 the same cylinder bank of the internal combustion engine 17 are assigned, wherein a donor cylinder concept is realized. Here are a total of six cylinders of the cylinder bank comprises, of which two cylinders as the first combustion chambers 3 and operated as a donor cylinder, with four cylinders as the second combustion chambers 7 and operated as a receiver cylinder. The combustion gas 5 the donor cylinder is thereby - over the second exhaust gas turbine 39 and the first cooling device 29 - the receiver cylinders 7 fed.

The combustion gas 5 is doing over the second exhaust gas turbine 39 preferably to the pressure level of the combustion air in the charging path 21 downstream of the first compressor 25 relaxes and prefers the second combustion chambers at this pressure level 7 fed. Only for the first combustion chambers 3 the charge air continues through the second compressor 35 compressed and thus these first combustion chambers 3 supplied at a higher pressure level. On the one hand, this makes sense for ensuring a favorable flushing gradient, on the other hand, preferably a combustion chamber operated with lean combustion is charged in two stages, while a stoichiometrically operated combustion chamber is preferably charged only in one stage. Especially for the lean-burned combustion chamber, it brings with it efficiency advantages, the highest possible combustion air mass and at the same time - with nevertheless lean combustion conditions - to be able to bring in an increased fuel mass. It is obvious that the same fuel mass can be burned with stoichiometric combustion with less air, so that with the same introduced fuel mass for the stoichiometric combustion results in a lower air requirement. It should also be noted that the of the internal combustion engine 17 Torque output substantially from that in the combustion chambers 3 . 7 introduced fuel mass depends.

It is a valve device 43 provided by means of the combustion gas 5 upstream of the second combustion chamber 7 combustion air 19 , here in particular charge air, can be fed. Preferably, the valve device is controllable, so that the combustion gas 5 supplied combustion air quantity is controlled or regulated. In this case, advantageously, a fresh air enrichment and in particular an increase in the oxygen content of the combustion gas 5 be achieved, resulting in a power increase in the second combustion chamber 7 can result. In addition, the exhaust gas recirculation rate for the second combustion chamber 7 In particular, it is possible to reduce the exhaust gas recirculation rate. The dispenser cylinder concept is with the lean-burn first combustor 3 very simple to carry out, since the sensitivity of the lean combustion process is lower than that of a stoichiometric combustion process. Thus, in a simple manner for the stoichiometrically operated part of the internal combustion engine 17 a high-pressure exhaust gas recirculation can be realized.

The valve device 43 is arranged here in a branch upstream of the second compressor. It is also possible that the valve device 43 downstream of the second intercooler 41 is arranged.

It should be noted that the donor cylinder concept, which in 2 is shown, in principle, can also be operated with a single-stage charge, in which case in particular the second exhaust gas turbocharger 35 eliminated. It then eliminates preferably the second intercooler 41 ,

3 shows a schematic representation of a third embodiment of the internal combustion engine device 1 , Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. Here, in particular, the first embodiment is according to 1 modified such that a two-stage charging is provided, so that in particular the second exhaust gas turbocharger 35 and the second intercooler 41 are provided. In addition, in addition, the valve device 43 provided by means of which the combustion gas 5 upstream of the second combustion chamber 7 Combustion air, here in particular charge air can be supplied. The charge air is here downstream of the first compressor 23 , in particular downstream of the first charge air cooler 27 , and upstream of the second compressor 37 diverted. As already stated, by means of the valve device 43 in particular, an oxygen content for the combustion gas 5 can be increased and an exhaust gas recirculation rate for the second combustion chamber 7 reducible. Also in this embodiment, the valve device 43 alternatively to the illustration according to 3 downstream of the second intercooler 41 be arranged.

Generally it is - in all embodiments - also possible that the valve device 43 upstream of the first compressor 25 or downstream of the second compressor 37 , or at another point of the charging path 21 is arranged.

It should be pointed out that, of course, only one of the two modifications shown here in comparison to the first embodiment can be provided. It is thus possible that starting from the embodiment according to 1 only the valve device 43 , but not the second turbocharger 35 and the second intercooler 41 is provided. It is also possible that only the second turbocharger 35 - Preferably in combination with the second intercooler 41 - but not the valve device 43 is provided.

4 shows a schematic representation of a fourth embodiment of the internal combustion engine device 1 , Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. In the embodiment shown here is a compressor device 45 provided for the compression of the combustion gas 5 is set up, wherein the compressor device 45 one of the combustion gas 5 permeable third compressor 47 having. This third compressor 47 is with a turbine 49 in Antriebswirkverbindung, wherein the turbine 49 here in a flow path 51 is arranged, the combustion air 19 is flowed through. The turbine 49 So it is with combustion air 19 charged and by the combustion air 19 driven. The compressed combustion gas 5 is then over the first cooling device 29 the second combustion chamber 7 fed. In this respect, the compressor device 45 here quasi designed as an exhaust gas recirculation pump, which the pressure level in the charging path 21 downstream of the first compressor 25 uses. In particular, that of the turbine 49 fed compressed combustion air downstream of the first compressor 25 and upstream of the intercooler 27 diverted.

In the flow path of the exhaust gas 5 is upstream of the third compressor 47 the compressor device 45 a second cooling device 53 arranged by combustion air 19 - especially downstream of the turbine 49 , So after flowing through the same - can be flowed through as a cooling medium. The low temperature level of the combustion air 19 , which in particular by the turbine 49 is again lowered, so here can advantageously for a first cooling of the combustion gas 5 be used. This is then after compression by the third compressor 47 additionally by the first cooling device 29 cooled.

5 shows a schematic representation of a fifth embodiment of the internal combustion engine 1 , Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. In this embodiment, in contrast to the fourth embodiment according to 4 - The second cooling device 53 from the combustion air 19 both before flowing through the turbine 49 as well as after flowing through the turbine 49 flows through as a cooling medium. In particular, the temperature level of the combustion air is first of all 19 downstream of the first compressor 25 for cooling the combustion gas 5 in the second cooling device 53 used, in which case the heated combustion air 19 in the turbine 49 relaxed and then the second cooling device 53 is returned to the combustion gas 5 continue to cool. The second cooling device 53 is here in a bypass or bypass path of the charging path 21 arranged, with the bypass or bypass path through the flow path 51 is formed. At the same time, the combustion air becomes 19 the charging path 21 both downstream of the first compressor 25 and upstream of the intercooler 27 taken as well as fed there again.

It is optionally possible that downstream of the second cooling device 53 in the flow path of the combustion gas 5 still a third cooling device 55 - In particular upstream of the third compressor 47 - is arranged. This third cooling device 55 is preferably not by combustion air 19 as a cooling medium, but by another cooling medium, particularly preferably by a liquid cooling medium, can flow. By means of the third cooling device 55 can the combustion gas 5 downstream of the second cooling device 53 and upstream of the third compressor 47 to be cooled even further.

6 shows a schematic representation of a sixth embodiment of the internal combustion engine device 1 , Identical and functionally identical elements are provided with the same reference numerals, so that reference is made to the preceding description. In this embodiment, the turbine is 49 the compressor device 45 in the flow path of the combustion gas 5 upstream of the third compressor 47 provided so that the combustion gas 5 even the turbine 49 drives, passing it after flowing through the turbine 49 from the third compressor 47 is compressed. It is downstream of the turbine 49 and upstream of the third compressor 47 a fourth cooling device 57 provided, with which the combustion gas 5 after flowing through the turbine 49 and before compression in the third compressor 47 is cooled so that it is compressed at a lower temperature level, which is lower than the temperature level at which it is in the turbine 49 is relaxed. After compression in the third compressor 47 becomes the combustion gas 5 again in the first cooling device 29 cooled before the second combustion chamber 7 is supplied.

It is therefore also an exhaust gas recirculation pump can be realized such that these by the combustion gas 5 self-powered.

An advantage of all embodiments described here is in particular also that the compressor of the exhaust gas turbocharger - regardless of whether a single-stage or multi-stage charging is provided - only the at least one first combustion chamber with compressed charge air supply, so a Aufladegruppe for the proposed here internal combustion engine device 1 can be smaller than in conventional internal combustion engines in which all combustion chambers are charged. In particular, it is possible with symmetrical distribution of the stroke volume of the internal combustion engine device on the first combustion chambers on the one hand and second combustion chambers on the other hand to make the Aufladegruppe half as large as in the realization of a conventional, identical combustion process in all combustion chambers.

In the same way it turns out that the three-way catalyst 11 can be made smaller than is the case with conventional internal combustion engines, since this only the exhaust gas of the second combustion chambers is fed to the aftertreatment. The exhaust gas mass flow in the three-way catalyst 11 is thus reduced compared to conventional internal combustion engine equipment. In particular, the three-way catalyst 11 - Are designed to be half as large at a symmetrically distributed to the first and second combustion chambers displacement - as in a conventional internal combustion engine.

Overall, it turns out that with the proposed internal combustion engine device 1 as well as the method proposed here for operating an internal combustion engine device 1 high efficiencies through consumption-optimized lean gas combustion in the first combustion chamber 3 can be realized, wherein the internal combustion engine device 1 at the same time suitable for exhaust gas purification in a three-way catalyst 11 so that it can have very low emissions and, in particular, cost advantages, especially over conventional SCR exhaust aftertreatment for the selective catalytic reduction of nitrogen oxides. This results in lower thermal loads than in a conventional, stoichiometrically operated gasoline engine. In addition, a high-pressure exhaust gas recirculation can be provided in a simple manner on the stoichiometrically operated engine without the need for external compressors for increasing the pressure of the recirculated exhaust gas.

Claims (10)

Method for operating an internal combustion engine device ( 1 ), wherein - a first combustion chamber ( 3 ) of the engine device ( 1 ) a first fuel is supplied, wherein - the first fuel in the first combustion chamber ( 3 ) is burned with excess air, wherein - oxygen-containing combustion gas ( 5 ) from the first combustion chamber ( 3 ) a second combustion chamber ( 7 ) of the engine device ( 1 ), wherein - the combustion gas ( 5 ) in the second combustion chamber ( 7 ) is reacted in a stoichiometric combustion, and wherein - exhaust gas ( 9 ) from the second combustion chamber ( 7 ) a three-way catalyst ( 11 ) is supplied. Method according to claim 1, characterized in that the first combustion chamber ( 3 ) A methane-containing fuel gas is supplied as the first fuel. Method according to one of the preceding claims, characterized in that the combustion gas ( 5 ) before flowing through an exhaust gas turbine ( 33 ), between a first exhaust gas turbine ( 39 ) and a second exhaust gas turbine ( 33 ), and / or after flowing through an exhaust gas turbine ( 39 ) of the second combustion chamber ( 7 ) is supplied. Method according to one of the preceding claims, characterized in that the combustion gas ( 5 ) upstream of the second combustion chamber ( 7 ) Combustion air ( 19 ), preferably charge air, is supplied. Method according to one of the preceding claims, characterized in that the combustion gas ( 5 ) upstream of the second combustion chamber ( 7 ) is heated or cooled. Method according to one of the preceding claims, characterized in that the combustion gas ( 5 ) upstream of the second combustion chamber ( 7 ), whereby a compressor ( 47 ) for the combustion gas ( 5 ) preferably by a turbine ( 49 ), with combustion air ( 19 ), in particular with charge air, or with combustion gas ( 5 ) is applied. Internal combustion engine device ( 1 ), with - a first combustion chamber ( 3 ), to which a first fuel can be supplied, wherein - the first fuel in the first combustion chamber ( 3 ) is combustible with excess air, wherein - the engine device ( 1 ) a second combustion chamber ( 7 ), the oxygen-containing combustion gas ( 5 ) from the first combustion chamber ( 3 ), wherein - the combustion gas ( 5 ) in the second combustion chamber ( 7 ) is convertible in a stoichiometric combustion, wherein - the engine device ( 1 ) a three-way catalyst ( 11 ), the exhaust gas ( 9 ) from the second combustion chamber ( 7 ) can be fed. Internal combustion engine device ( 1 ) according to claim 7, characterized in that the first combustion chamber ( 3 ) and the second combustion chamber ( 7 ) a) are assigned to different internal combustion engines, or b) the same internal combustion engine ( 17 ), wherein they c) different cylinder banks ( 13 . 15 ) and / or wherein d) the first combustion chamber ( 3 ) as a donor cylinder and the second combustion chamber ( 7 ) are designed as a receiver cylinder. Internal combustion engine device ( 1 ) according to one of claims 7 and 8, characterized in that the engine device ( 1 ) a compressor device ( 45 ) for the compression of the combustion gas ( 5 ), the compressor device ( 45 ) one of the combustion gas ( 5 ) throughflowable compressor ( 47 ), which is equipped with a turbine ( 49 ) in drive-mode connection, wherein the turbine a) in the flow path of the combustion gas ( 5 ) upstream of the compressor ( 47 ), or b) in a flow path ( 51 ), which is set up in accordance with its intended purpose, in order to communicate with combustion air ( 19 ), in particular with charge air, to be acted upon. Internal combustion engine device ( 1 ) according to one of claims 7 to 9, characterized in that upstream of the compressor ( 47 ) of the compressor device ( 45 ) a cooling device ( 53 ) for cooling the combustion gas ( 5 ), wherein the cooling device ( 53 ) of combustion air ( 19 ), in particular of charge air, preferably after flowing through the turbine ( 49 ) and / or before flowing through the turbine ( 49 ), can be flowed through as a cooling medium.

Images