DE102010017558A1 - Internal combustion engine for driving motor vehicles, has cylinder head and turbine, where dosing device, which is provided for dosing liquid coolant in cavity for evaporation - Google Patents

Abstract

The internal combustion engine has a cylinder head (2) and a turbine (6a), where a dosing device (11), which is provided for dosing a liquid coolant in a cavity for evaporation. An injection device is provided with a fuel injector, where a turbine housing (8) is provided, which is made of aluminum material. An independent claim is also included for a method for operating an internal combustion engine.

Description

• – der mindestens eine Zylinderkopf mindestens einen Zylinder umfaßt, wobei jeder Zylinder mindestens eine Auslaßöffnung zum Abführen der Abgase aus dem Zylinder aufweist und sich an jede Auslaßöffnung eine Abgasleitung anschließt, und
• – die mindestens eine ein Turbinengehäuse aufweisende Turbine zur Nutzung der Abgasenthalpie mit mindestens einer Abgasleitung verbunden ist, wobei das Turbinengehäuse zur Ausbildung einer Kühlung mit einem kühlmittelmantelähnlichen Hohlraum ausgestattet ist.

The invention relates to an internal combustion engine having at least one cylinder head and at least one turbine, wherein

• - The at least one cylinder head comprises at least one cylinder, each cylinder having at least one outlet opening for discharging the exhaust gases from the cylinder and connects to each outlet opening an exhaust pipe, and
• - The at least one turbine housing having a turbine for using the exhaust gas enthalpy is connected to at least one exhaust pipe, wherein the turbine housing is equipped to form a cooling with a coolant jacket-like cavity.

Furthermore, the invention relates to a method for operating such an internal combustion engine.

Internal combustion engines of the above type are used as a drive for motor vehicles. In the context of the present invention, the term internal combustion engine includes diesel engines and gasoline engines, but also hybrid internal combustion engines, d. H. Internal combustion engines operated by a hybrid combustion process.

Internal combustion engines have a cylinder block and a cylinder head which are used to form the at least one cylinder, i. H. Combustor, to be interconnected. The cylinder block has a corresponding number of cylinder bores for receiving the pistons or the cylinder tubes. The pistons are guided axially movably in the cylinder tubes and, together with the cylinder tubes and the cylinder head, form the combustion chambers of the internal combustion engine.

The cylinder head is usually used to hold the valve train. In order to control the charge cycle, an internal combustion engine requires control devices, i. H. Valves, and actuators for actuating the control members. As part of the charge exchange, the exhaust of the combustion gases via the outlet openings and the filling of the combustion chamber, d. H. the suction, over the inlet openings. The required for the movement of the valves valve actuating mechanism including the valves themselves is referred to as a valve train.

The inlet ducts leading to the inlet openings and the outlet ducts or exhaust ducts adjoining the outlet openings are at least partially integrated in the cylinder head according to the prior art. The exhaust pipes of the cylinders are combined in groups, often to a single overall exhaust line. The merging of exhaust pipes to a common exhaust pipe is generally and also referred to in the context of the present invention as an exhaust manifold.

Downstream of the at least one cylinder, the exhaust gases are optionally supplied via the exhaust pipe to the turbine of an exhaust gas turbocharger and / or one or more exhaust aftertreatment systems.

It is on the one hand endeavored to arrange the turbine of the exhaust gas turbocharger as close to the outlet of the engine to optimally use in this way the exhaust enthalpy of the hot exhaust gases, which is largely determined by the exhaust pressure and the exhaust gas temperature, and a quick response of the turbocharger guarantee. On the other hand, the way the hot exhaust gases to the various exhaust aftertreatment systems should be as short as possible, so that the exhaust gases are given little time to cool and the exhaust aftertreatment systems reach their operating temperature or light-off as soon as possible, especially after a cold start of the engine.

The arrangement of the turbine, which is as close to the engine as possible, means that the turbine is subjected to a high thermal load by the hot combustion gases. It should also be taken into account in this connection that the thermal load caused by charging increases considerably again. For the production of the turbine, in particular of the turbine housing, therefore thermally highly resilient materials are required.

The production costs for such a turbine are very high due to the use of these thermally highly resilient - often nickel-containing - materials, especially in comparison to the costs that would arise when using the actually preferred material, namely aluminum. Not only the materials as such, d. H. The material costs lead to an increase in costs, but also the more cost-intensive processing of these heavy-duty materials, d. H. the processing costs.

It follows from the foregoing that in terms of cost, it would be highly advantageous if a turbine could be provided that could be made from a less expensive material, such as aluminum.

The use of aluminum would also be advantageous in terms of the weight of the turbine. In particular, when it is taken into account that the engine-near arrangement of the turbine leads to a relatively large-sized, voluminous housing. Because the connection of turbine and cylinder head by means of flange and screws requires due to the limited space a large turbine inlet area, also because sufficient space must be provided for the assembly tools. The voluminous housing brings a correspondingly high weight with it. The weight advantage of aluminum over a highly resilient material is particularly evident in a turbine arranged close to the engine due to the comparatively high use of materials.

In the prior art, turbines are already equipped with liquid cooling, also to allow the use of aluminum for the manufacture of the turbine housing. As a result of the cooling of the thermally highly loaded turbine can be dispensed with heat plates to protect adjacent components from high temperatures.

To form a liquid cooling, the turbine housing is usually equipped with a coolant jacket, said coolant jacket can be supplied via the liquid cooling of the internal combustion engine with coolant, for example by a coolant jacket integrated in the cylinder head is connected to the coolant jacket of the turbine. A liquid-cooled turbine of this type is used for example in the US 3,948,052 A described.

The EP 1 384 857 A2 also discloses a turbine whose housing is equipped with a coolant jacket.

Due to the high specific heat capacity of a liquid, in particular the water usually used, the housing by means of liquid cooling large amounts of heat can be withdrawn. The heat is released inside the housing to the coolant and removed with the coolant. The heat given off to the coolant is withdrawn from the coolant in a heat exchanger.

In principle, it is possible to equip the liquid cooling of the turbine with a separate heat exchanger or - in a liquid-cooled internal combustion engine - the heat exchanger of the engine cooling, d. H. to use the heat exchanger of another liquid cooling, for this purpose. The latter requires only appropriate connections of both circuits.

However, it should be noted in this connection that the amount of heat absorbed by the coolant in the turbine can be 40 kW or more. The coolant to extract such a large amount of heat in the heat exchanger and dissipate by means of air flow to the environment turns out to be problematic.

Although modern motor vehicle drives are equipped with powerful fan motors to the heat exchangers of the cooling systems even at a standstill, d. H. to provide the air mass flow required for a sufficiently high heat transfer when the vehicle is stationary, or at low vehicle speeds. And such fans can basically increase the heat transfer in the heat exchangers. But another, relevant for the heat transfer parameters, namely the surface provided for the heat transfer, can not be made arbitrarily large or enlarged, since the space in the front-end area of the vehicle, where the various heat exchangers usually arranged be limited.

Modern motor vehicles often have - in addition to the heat exchanger of the engine cooling - on other heat exchangers, in particular cooling devices.

On the intake side of an internal combustion engine, a charge air cooler is often arranged in order to increase the density of the fresh cylinder charge and to contribute to a better filling of the at least one cylinder. Usually supercharged internal combustion engines are equipped with a charge air cooler.

In order to maintain a maximum permissible oil temperature, the heat release via the oil sump as a result of heat conduction and natural convection often no longer suffices, so that in individual cases an oil cooler must be provided.

In addition, modern internal combustion engines are increasingly being equipped with exhaust gas recirculation (EGR). The exhaust gas recirculation is a measure to counteract the formation of nitrogen oxides, which requires an excess of air and high temperatures, as the exhaust gas recirculation is a means of lowering the temperatures.

In order to achieve a significant reduction in nitrogen oxide emissions, high exhaust gas recirculation rates x _{EGR are} required, which may be on the order of x _AGR = 50% to 70% with x _AGR = m _EGR / (m _EGR + m _{fresh air} ), where m _{AGR is} the Mass of recirculated exhaust gas and _{fresh air} m denotes the supplied and optionally compressed fresh air or charge air.

To realize these high recirculation rates, cooling of the recirculated exhaust gas, ie compression of the exhaust gas by cooling, is absolutely necessary in order to reduce the density of the recirculated exhaust gas Increase exhaust gas. The internal combustion engine is therefore equipped with an additional cooling device for cooling the recirculating exhaust gas.

Other coolers can be provided, for example for cooling the transmission oil in automatic transmissions and / or for cooling hydraulic fluids, in particular hydraulic oil, which is used in the context of hydraulically actuated adjusting devices or for steering assistance. The air conditioning condenser of an air conditioning system is also a heat exchanger, which has to give off heat to the environment during operation, so requires a sufficiently high air flow and therefore is to be arranged in the front-end area.

Due to the very tight space conditions in the front-end area and the large number of heat exchangers, the actually required cooling demand of each individual heat exchanger can be taken into account only to a limited extent. The dimensioning and arrangement of the heat exchanger in the front-end region of the vehicle, also to each other, requires a compromise in the prior art, as an optimized in terms of heat transfer arrangement and dimensioning of all heat exchangers is not possible.

The possibility of arranging a separate and sufficiently large heat exchanger for the liquid cooling of the turbine in the front-end region or to dimension the heat exchanger of the engine cooling of a liquid-cooled internal combustion engine so large that it can be dissipated via this additional heat extracted from the turbine, is not given.

Therefore, other measures are required with which the amount of heat introduced into the coolant as part of the cooling of the turbine can be withdrawn from the coolant, or to show concepts of how to design the cooling of the turbine in order to cope with such large amounts of heat.

Against the background of the above, it is an object of the present invention to provide an internal combustion engine according to the preamble of claim 1, d. H. of the generic type, which is optimized for cooling the turbine.

A further sub-task of the present invention is to show a method for operating such an internal combustion engine.

• – der mindestens eine Zylinderkopf mindestens einen Zylinder umfaßt, wobei jeder Zylinder mindestens eine Auslaßöffnung zum Abführen der Abgase aus dem Zylinder aufweist und sich an jede Auslaßöffnung eine Abgasleitung anschließt, und
• – die mindestens eine ein Turbinengehäuse aufweisende Turbine zur Nutzung der Abgasenthalpie mit mindestens einer Abgasleitung verbunden ist, wobei das Turbinengehäuse zur Ausbildung einer Kühlung mit einem kühlmittelmantelähnlichen Hohlraum ausgestattet ist,

und die dadurch gekennzeichnet ist, dass

• – eine Dosiereinrichtung vorgesehen ist, die dem Einbringen von flüssigem Kühlmittel in den Hohlraum zum Zwecke der Verdampfung dient, wobei zur Ausbildung eines Kühlmittelkreislaufs eine Abführleitung zum Abführen des verdampften Kühlmittels aus dem Hohlraum und eine Rückführleitung zur Versorgung der Dosiereinrichtung mit dem erneut verflüssigten Kühlmittel vorgesehen sind.

The first sub-task is solved by an internal combustion engine with at least one cylinder head and at least one turbine, in which

• - The at least one cylinder head comprises at least one cylinder, each cylinder having at least one outlet opening for discharging the exhaust gases from the cylinder and connects to each outlet opening an exhaust pipe, and
• - The at least one turbine housing having a turbine for using the exhaust gas enthalpy is connected to at least one exhaust pipe, wherein the turbine housing is equipped to form a cooling with a coolant jacket-like cavity,

and which is characterized in that

• - A metering device is provided which serves to introduce liquid coolant into the cavity for the purpose of evaporation, wherein for forming a coolant circuit, a discharge line for discharging the evaporated refrigerant from the cavity and a return line for supplying the metering device are provided with the re-liquefied coolant ,

To form the cooling according to the invention, the turbine housing is equipped with a coolant jacket-like cavity, d. H. with a cavity that resembles or corresponds to the coolant jacket of a liquid-cooled turbine. In this cavity, liquid coolant is introduced by means of a metering device. The coolant evaporates and removes heat from the turbine or the turbine housing. A discharge line and a return line serve to close the coolant circuit.

According to the invention, the at least one turbine is not equipped with a liquid cooling in the conventional sense, but rather with a cooling, which is based on the principle of evaporation of a liquid coolant.

This procedure in the cooling of the turbine has several advantages, with the technical effects complement each other or cooperate in an advantageous manner, d. H. There are synergies. On the one hand, by using a comparatively small amount of coolant, the turbine can be deprived of a large amount of heat by evaporating the coolant. On the other hand, the enthalpy inherent in the vaporous coolant, namely the heat introduced into the coolant by means of evaporation, can be utilized in a variety of ways.

For this reason, embodiments of the internal combustion engine are particularly advantageous in which a device for using the enthalpy of the vaporized coolant is provided in the discharge line. In contrast to the state of the art, that in the turbine is replaced by the coolant absorbed heat not dissipated unused in a heat exchanger to the environment.

Rather, the introduced into the coolant heat is made available by pressure and / or temperature reduction of the vaporized coolant and used again, whereby the overall efficiency of the internal combustion engine is increased. The inevitably associated decrease in enthalpy can lead to or contribute to a renewed liquefaction of the vaporous coolant, which is also desired or required in order to supply the metering device in a closed coolant circuit continuously with liquid coolant.

Thus, the first object of the invention is achieved, namely to provide an internal combustion engine according to the preamble of claim 1, which is optimized with respect to the cooling of the turbine.

The internal combustion engine according to the invention has a turbine which is connected to at least one exhaust pipe to utilize the exhaust gas enthalpy. The turbine may be part of an exhaust gas turbocharger, but need not necessarily be part of an exhaust gas turbocharger.

Nevertheless, embodiments of the internal combustion engine are advantageous in which the turbine connected to at least one exhaust pipe is the turbine of an exhaust gas turbocharger.

The charge is used primarily to increase the performance of the internal combustion engine. The air required for the combustion process is compressed, which allows each cylinder per cycle more air mass can be supplied. As a result, the fuel mass and thus the mean pressure p _{me can be} increased.

The charge is therefore a suitable means to increase the capacity of an internal combustion engine with unchanged displacement, or to reduce the displacement at the same power. At the same vehicle boundary conditions, the load collective can thus be shifted to higher loads. The fuel consumption of the internal combustion engine is reduced and the efficiency is improved.

In an exhaust gas turbocharger, a compressor and a turbine are arranged on the same shaft, wherein the hot exhaust gas flow is supplied to the turbine by means of exhaust pipe and relaxes with energy release in this turbine, whereby the shaft is rotated. The energy emitted by the exhaust gas flow to the turbine and finally to the shaft is used to drive the compressor, which is also arranged on the shaft. The compressor conveys and compresses the charge air supplied to it by means of intake line, whereby charging of the internal combustion engine is achieved.

The advantage of an exhaust gas turbocharger, for example compared to a mechanical supercharger, is that there is no mechanical connection to the power transmission between the supercharger and the internal combustion engine. While a mechanical supercharger obtains the energy needed for its drive from the internal combustion engine, the exhaust gas turbocharger uses the energy of the hot exhaust gases generated by the internal combustion engine, d. H. the exhaust enthalpy.

Further advantageous embodiments of the internal combustion engine are discussed in connection with the subclaims.

The enthalpy of the vaporized coolant can be used in a variety of ways, i. H. be made available, the recovery is based in principle on a pressure and / or temperature reduction of the vaporized coolant. The devices used can be correspondingly different for the utilization of the enthalpy of the coolant.

Embodiments of the internal combustion engine in which a piston engine is provided in the discharge line as a device for utilizing the enthalpy of the evaporated coolant are advantageous, for example.

However, embodiments of the internal combustion engine in which a turbomachine is provided in the discharge line as a device for using the enthalpy of the evaporated coolant are also particularly advantageous.

Both the first-mentioned reciprocating engine and the turbomachine are expansion machines, which withdraw the energy from the vaporized and usually superheated coolant by a pressure reduction in the context of an expansion.

Both expansion machines are suitable for providing the energy extracted from the vaporous coolant for further use, for example at the crankshaft of the internal combustion engine or else for driving ancillary components. This improves the energy balance and the efficiency of the internal combustion engine. For the same fuel use, the power or energy output of the internal combustion engine is increased. An expansion machine is thus suitable for utilizing the energy bound in the coolant in order to increase the power output of the internal combustion engine.

In contrast to a piston engine, which - like the internal combustion engine itself - is operated intermittently, ie operates in cycles, and the vaporous refrigerant is supplied in portions, a turbomachine is characterized by a continuous operation, in which the continuous flow machine continuous vapor refrigerant is supplied.

A turbomachine has a higher efficiency due to the continuous flow than a piston engine.

It should be noted that expansion machines, such as piston engines having one or more pistons, but are continuously flowed through, are not assigned in the context of the present invention, the piston engines, but rather the turbomachines. An example of such an expansion machine is a Roots blower, which usually has two pistons and is continuously flowed through.

If the device for utilizing the coolant enthalpy is a turbomachine, in particular embodiments of the internal combustion engine are advantageous in which the turbomachine is a steam turbine.

A turbine has on the one hand due to the continuous flow to a comparatively high efficiency. On the other hand, separately installable turbines are available in a variety of designs for motor vehicle construction. In addition, there are sufficient findings for the use of such expansion engines in internal combustion engines.

In addition, the shaft of a turbine can be connected in a simple manner with the crankshaft of an internal combustion engine for power transmission or coupled with a traction mechanism, which serves for example for the drive of ancillaries.

For this reason, embodiments of the internal combustion engine are also advantageous in which the serving as a device for using the enthalpy of coolant turbine for power output is connected to the crankshaft or connectable, optionally with the interposition of a clutch.

Embodiments of the internal combustion engine in which a heat exchanger is provided as a device for utilizing the enthalpy of the evaporated coolant in the discharge line are advantageous.

In contrast to an expansion machine, the heat exchanger extracts the energy from the evaporated coolant by heat transfer, which primarily causes a drop in temperature in the coolant and only indirectly leads to a reduction in pressure. The heat removed from the coolant can be introduced into another process fluid, for example after a cold start in the engine oil to shorten the warm-up phase, or be used to heat an air flow.

Advantageous embodiments of the internal combustion engine, in which the coolant circuit is equipped with a condenser to liquefy the coolant.

The fact that it is in the cooling of the turbine to a closed coolant circuit and the supply of the metering device with liquid coolant makes a complete liquefaction of the vaporized coolant upstream of the metering necessary, may require the equipment of the coolant circuit with a capacitor in an individual case.

A condenser is therefore always required when the pressure and / or temperature drop of the coolant in the device for utilizing the enthalpy of the coolant is not sufficiently large to completely liquefy the vaporous coolant or to ensure that the coolant entering the Metering device is present in the liquid phase.

It should be noted in this context that it may be disadvantageous to liquefy the vaporized coolant - even partially - in the expansion machine. If the vaporous coolant returns to the liquid state of aggregation, its volume decreases abruptly, which can lead to high mechanical stresses on the piston engine or the turbine, possibly causing irreparable damage and leading to the destruction of the expansion engine.

In this respect, it may be advantageous for the vaporized superheated coolant to leave the expansion machine essentially in vapor form and for the condenser arranged downstream in the return line to return the coolant to the liquid phase before it enters the metering device.

Embodiments of the internal combustion engine in which the metering device comprises an injection device are advantageous. The introduction of the fuel by means of injection is extremely advantageous. The liquid fuel is more or less finely atomized as part of the injection and in dependence on the injection pressure, whereby a coolant mist is formed and the surface of the coolant is greatly increased. The coolant droplets evaporate on contact with the inner walls the cavity at least partially. The heat of vaporization is removed from the turbine housing and the housing temperature drops.

In this context, embodiments of the internal combustion engine in which the injection device has at least one injection nozzle are advantageous.

Embodiments of the internal combustion engine in which the turbine housing is at least partially made of aluminum are advantageous. This brings cost benefits compared to the use of conventional materials. In addition, the use of aluminum for the manufacture of the turbine housing leads to a lower weight.

Due to the high cooling capacity of the cooling according to the invention can be completely or at least partially dispensed with the use of thermally highly resilient materials for the production of the turbine or the turbine housing. The use of cost-intensive - often nickel-containing - materials according to the invention is no longer necessary or greatly reduced.

Advantageous embodiments of the internal combustion engine, in which the turbine housing is a casting, d. H. the blank of the housing, which is optionally nachzubearbeiten. This manufacture of the housing allows the formation of an advantageous cavity.

Embodiments of the internal combustion engine in which the at least one cylinder head has at least one integrated coolant jacket to form a liquid cooling are advantageous.

The liquid cooling requires the equipment of the cylinder head with a coolant jacket, d. H. the arrangement of the coolant through the cylinder head leading coolant channels. The heat is already released inside the cylinder head to the coolant. The coolant is conveyed by means of a pump arranged in the cooling circuit, so that it circulates in the coolant jacket. The heat given off to the coolant is withdrawn from the coolant in a heat exchanger.

With a liquid cooling can be dissipated compared to an air cooling much larger amounts of heat. With appropriate design of the liquid cooling or corresponding cooling performance of the cylinder head may under certain circumstances be made entirely or at least in parts of aluminum, which brings cost advantages over the use of high-temperature austenitic steel. The use of aluminum for the production of the cylinder head also leads to a weight saving.

The liquid cooling of the cylinder head is particularly suitable for supercharged internal combustion engines, which require efficient and optimized cooling due to the higher exhaust gas temperatures.

In addition, an efficient liquid cooling prevents the thermal overload of the internal combustion engine, without a richening (λ <1) is required to lower the exhaust gas temperatures. When enriched, more fuel is injected than can be burned at all with the amount of air provided. The excess fuel is also heated and vaporized, thereby lowering the temperature of the combustion gases. This approach is disadvantageous in terms of fuel consumption and pollutant emissions. In addition, the enrichment does not always allow the internal combustion engine to be operated in the manner required, for example, for an exhaust aftertreatment system.

The liquid cooling allows the stoichiometric operation (λ ≈ 1) of a gasoline engine even at high loads.

In the embodiment in question, d. H. a liquid-cooled internal combustion engine, in addition, the cooling of the turbine via engine cooling can be supplied with coolant.

Therefore, embodiments of the internal combustion engine are advantageous in which the liquid cooling is in communication with the coolant circuit of the turbine housing.

The integrated in the cylinder head coolant jacket can be connected, for example, with the coolant jacket-like cavity of the turbine, the coming out of the cavity discharge line leads to the cylinder head and the return line branches off from the coolant jacket of the cylinder head and connected to the metering device to supply them with liquid coolant. On further coolant lines can be dispensed with.

Advantageous embodiments of the internal combustion engine, in which each cylinder has at least two outlet openings for discharging the exhaust gases from the cylinder. During the expulsion of the exhaust gases in the context of the charge exchange, it is a primary goal, as quickly as possible to release the largest possible flow cross-sections, to ensure effective discharge of the exhaust gases, which is why the provision of more than one outlet opening is advantageous.

For similar reasons, it is advantageous to provide two or more inlet openings to keep the throttle losses in the inflowing gas flows low and to ensure the best possible filling of the combustion chamber with fresh mixture.

But can also be advantageous embodiments of the cylinder head, in which each cylinder has only one outlet opening for discharging the exhaust gases from the cylinder.

In internal combustion engines having at least two cylinders, embodiments are advantageous in which the exhaust gas lines of at least two cylinders bring together at least one integrated exhaust manifold within the cylinder head to form an overall exhaust gas line. Advantages arise in particular with regard to a motor-near arrangement of the turbine.

The length of the exhaust pipes is reduced by integration into the cylinder head. On the one hand thereby the line volume, d. H. the exhaust volume of the exhaust pipes, upstream of the turbine reduced, so that the response of the turbine is improved. On the other hand, the shortened exhaust pipes also lead to a lower thermal inertia of the exhaust system upstream of the turbine, so that the temperature of the exhaust gases at the turbine inlet is higher, which is why the enthalpy of the exhaust gases at the inlet of the turbine is higher and optionally provided downstream of the turbine exhaust aftertreatment faster reach required operating temperature.

The merging of the exhaust pipes within the cylinder also allows tight packaging of the drive unit.

If the at least two cylinders of an internal combustion engine have two or more outlet openings, embodiments of the internal combustion engine are advantageous in which first the exhaust lines of the at least two outlet openings of each cylinder merge to form a partial exhaust line belonging to the cylinder before the partial exhaust lines of at least two cylinders combine to form an overall exhaust line.

The total travel distance of all exhaust pipes is thereby shortened. The gradual merging of the exhaust pipes to an overall exhaust line also contributes to a more compact, d. H. less voluminous design of the cylinder head and thus in particular to a weight reduction and a more effective packaging in the engine compartment.

The turbine can be equipped with a variable turbine geometry, which allows a further adaptation to the respective operating point of the internal combustion engine by adjusting the turbine geometry or the effective turbine cross section. In this case, guide vanes for influencing the flow direction are arranged in the inlet region of the turbine. Unlike the vanes of the rotating impeller, the vanes do not rotate with the shaft of the turbine.

If the turbine has a fixed invariable geometry, the vanes are not only stationary, but also completely immovable in the entry area, i. H. rigidly fixed. If, on the other hand, a turbine with variable geometry is used, the guide vanes are indeed arranged stationary, but not completely immobile, but rotatable about their axis, so that the flow of the blades can be influenced.

Both embodiments in which the turbine is an axial turbine and also embodiments in which the turbine is a radial turbine are advantageous.

The turbine can also be a twin-flow turbine. A double-flow turbine has an inlet region with two inlet channels, wherein two exhaust gas lines are connected to the twin-flow turbine in such a way that in each case an exhaust pipe opens into an inlet channel.

• – flüssiges Kühlmittel mittels Dosiereinrichtung in den Hohlraum eingebracht wird,
• – das eingebrachte Kühlmittel verdampft wird, wodurch dem Turbinengehäuse Wärme entzogen wird, und
• – das verdampfte Kühlmittel via Abführleitung abgeführt wird.

The second sub-task, namely to show a method for operating an internal combustion engine according to one of the aforementioned types, is achieved by a method which is characterized in that

• - Liquid coolant is introduced by means of metering device in the cavity,
• - The introduced coolant is evaporated, whereby the turbine housing heat is removed, and
• - The vaporized coolant is discharged via the discharge line.

What has already been said for the internal combustion engine according to the invention also applies to the method according to the invention, which is why reference is generally made at this point to the statements made above with regard to the internal combustion engine.

According to the different embodiments of the internal combustion engine, different process variants result.

Process variants in which the enthalpy of the evaporated coolant is used by means of a device provided in the discharge line are particularly advantageous. The heat extracted as part of the cooling is effectively called Temperature and pressure increase stored in the coolant. The device serves to recover this energy introduced into the coolant.

Also particularly advantageous are process variants in which the liquid coolant is introduced by injection into the cavity.

Advantageous are process variants in which a coolant is used, which is characterized by a high enthalpy of vaporization.

In the following the invention is based on three embodiments according to the 1 to 3 described in more detail. Hereby shows:

1 schematically a first embodiment of the internal combustion engine,

2 schematically a second embodiment of the internal combustion engine, and

3 schematically a third embodiment of the internal combustion engine.

1 schematically shows a first embodiment of the internal combustion engine 1 , At the in 1 illustrated embodiment is a three-cylinder in-line engine 1 in which the three cylinders 3 along the longitudinal axis of the cylinder head 2 , ie in series, are arranged. For discharging the hot combustion gases is an exhaust pipe 5 and to supply the cylinders 3 with fresh air or fresh mixture a suction line 4 intended.

The internal combustion engine 1 is for the purpose of charging with an exhaust gas turbocharger 6 equipped, being in the exhaust pipe 5 a turbine 6a and in the intake pipe 4 a compressor 6b are arranged. The cylinders 3 supplied fresh air is in the compressor 6b compressed, including the enthalpy of the exhaust gas flow in the turbine 6a is being used. The charge increases the thermal load of the internal combustion engine 1 ,

Downstream of the compressor 6b is a charge air cooler 7 in the intake pipe 4 arranged to lower the temperature of the compressed charge air. In this way, the density of the air is increased, resulting in better filling of the cylinder 3 is realized.

The turbine 6a the exhaust gas turbocharger 6 has a turbine housing 8th that is to form a cooling 9 is equipped with a coolant jacket-like cavity (symbolized by serpentine lines). The cooling 9 serves to protect the turbine 6a Overheating and allows a largely waiver of high temperature resistant materials despite the high exhaust gas temperatures of a supercharged internal combustion engine 1 ,

The cooling 9 is as a closed coolant circuit 10 educated. To the turbine 6a to cool, is by means of metering device 11 liquid coolant into the cavity in the housing 8th integrated, introduced. The coolant evaporates and escapes from the housing 8th heat. The vaporized coolant is via discharge line 12 removed from the cavity. After liquefaction, the coolant of the metering device 11 via return line 13 provided and re-introduced into the cavity.

To use the enthalpy of the vaporized coolant is in the discharge line 12 a device 14 arranged. At the in 1 illustrated embodiment is as a device 14 to use the enthalpy of the coolant, a steam turbine 17 ie an expansion machine 15 , intended.

The turbine 17 has a high efficiency due to the continuous flow and can be connected to the power output in a simple manner with the crankshaft or coupled with a traction drive (not shown).

Downstream of the turbine 17 is a capacitor 18 in the coolant circuit 10 provided to liquefy the coolant completely. Advantageously, the vaporized coolant should be the turbine 17 Leave substantially still vapor, since the vapor refrigerant in its transition into the liquid state of aggregation abruptly reduces its volume, resulting in damage to the turbine 17 can lead.

2 schematically shows a second embodiment of the internal combustion engine 1 , It should only the differences to the in 1 Otherwise, reference will be made to FIG 1 and the corresponding description. The same reference numerals have been used for the same components.

Unlike the in 1 embodiment shown is in the in 2 illustrated internal combustion engine 1 as a device 14 to use the enthalpy of the vaporized coolant, a reciprocating engine 16 in the discharge line 12 arranged.

Like the steam turbine of the 1 illustrated embodiment is also the piston engine 16 an expansion machine 15 which extracts the energy from the vaporized coolant by depressurizing in the course of expansion. Unlike a steam turbine, the piston engine works 16 but intermittently with an oscillating Stroke movement of the piston (indicated by double arrow).

3 schematically shows a third embodiment of the internal combustion engine 1 , It should only the differences to the in 1 Otherwise, reference will be made to FIG 1 and the corresponding description. The same reference numerals have been used for the same components.

Unlike the in 1 embodiment shown is in the in 3 illustrated internal combustion engine 1 as a device 14 to use the enthalpy of the vaporized coolant, a heat exchanger 19 in the discharge line 12 intended.

Unlike an expansion machine, the heat exchanger uses 19 the energy bound in the vaporized coolant by heat removal, which leads to a lowering of the temperature of the coolant. The heat extracted from the coolant can be used in a variety of ways, for example for heating the engine oil after a cold start.

A condenser for liquefaction is not required because the coolant completely, ie completely, in the heat exchanger 19 can be liquefied.

LIST OF REFERENCE NUMBERS

1

Internal combustion engine

2

cylinder head

3

cylinder

4

suction

5

exhaust pipe

6

turbocharger

6a

turbine

6b

compressor

7

Intercooler

8th

turbine housing

9

turbine cooling

10

Coolant circuit

11

metering

12

discharge

13

Return line

14

Device for using the enthalpy of the vaporized coolant

15

expander

16

piston engine

17

steam turbine

18

capacitor

19

heat exchangers

kW

kilowatt

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US Pat. No. 3,944,052 A [0014]
• EP 1384857 A2 [0015]

Claims (14)

Internal combustion engine ( 1 ) with at least one cylinder head ( 2 ) and at least one turbine ( 6a ), in which - the at least one cylinder head ( 2 ) at least one cylinder ( 3 ), each cylinder ( 3 ) at least one outlet opening for discharging the exhaust gases from the cylinder ( 3 ) and at each outlet opening an exhaust pipe ( 5 ), and - the at least one turbine housing ( 8th ) having turbine ( 6a ) to use the exhaust gas enthalpy with at least one exhaust pipe ( 5 ), the turbine housing ( 8th ) to form a cooling ( 9 ) is provided with a coolant jacket-like cavity, characterized in that - a metering device ( 11 ) is provided, which serves for the introduction of liquid coolant into the cavity for the purpose of evaporation, wherein for forming a coolant circuit ( 10 ) a discharge line ( 12 ) for removing the evaporated coolant from the cavity and a return line ( 13 ) for supplying the metering device ( 11 ) are provided with the re-liquefied coolant. Internal combustion engine ( 1 ) according to claim 1, characterized in that in the discharge line ( 12 ) a device ( 14 ) is provided to use the enthalpy of the vaporized coolant. Internal combustion engine ( 1 ) according to claim 2, characterized in that in the discharge line ( 12 ) a piston machine ( 16 ) as a device ( 14 ) is provided to use the enthalpy of the vaporized coolant. Internal combustion engine ( 1 ) according to claim 2, characterized in that in the discharge line ( 12 ) a turbomachine as a device ( 14 ) is provided to use the enthalpy of the vaporized coolant. Internal combustion engine ( 1 ) according to claim 4, characterized in that in the discharge line ( 12 ) as turbomachine a steam turbine ( 17 ) is provided. Internal combustion engine ( 1 ) according to claim 2, characterized in that in the discharge line ( 12 ) a heat exchanger ( 19 ) as a device ( 14 ) is provided to use the enthalpy of the vaporized coolant. Internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that the coolant circuit ( 10 ) with a capacitor ( 18 ) to liquefy the coolant. Internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that the metering device ( 11 ) comprises an injection device. Internal combustion engine ( 1 ) according to claim 8, characterized in that the injection device has at least one injection nozzle. Internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that the turbine housing ( 8th ) is at least partially made of aluminum. Internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that the at least one cylinder head ( 2 ) to form a liquid cooling at least one integrated coolant jacket. Internal combustion engine ( 1 ) according to claim 11, characterized in that the liquid cooling is in communication with the coolant circuit ( 10 ) of the turbine housing ( 8th ). Method for operating an internal combustion engine ( 1 ) according to one of the preceding claims, characterized in that - liquid coolant by means of metering device ( 11 ) is introduced into the cavity, - the introduced coolant is evaporated, whereby the turbine housing ( 8th ) Heat is withdrawn, and - the vaporized coolant via discharge line ( 12 ) is discharged. A method according to claim 13, characterized in that - the enthalpy of the vaporized coolant by means of a in the discharge line ( 12 ) device ( 14 ) is being used.

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