DE102015008668A1 - Internal combustion engine for a motor vehicle - Google Patents

Abstract

The invention relates to an internal combustion engine (10) for a motor vehicle, having at least one combustion chamber (14) with an intake tract (28) through which air can flow from the combustion chamber (14), with at least one compressor (50) arranged in the intake tract (28). for compressing the air to be supplied to the combustion chamber (14), and with at least one charge air cooler (52) arranged in the intake duct (28) downstream of the compressor (50) for cooling the compressed air, the charge air cooler (52) being adapted to cause condensation to effect water contained in the compressed air, wherein at least one container (56) for receiving the condensed water and a supply means (62) are provided, by means of which the condensed water from the container (56) of the compressed air can be fed.

Description

The invention relates to an internal combustion engine for a motor vehicle according to the preamble of patent claim 1.

Such an internal combustion engine for a motor vehicle, in particular passenger cars, for example, is already the DE 10 2007 045 347 A1 to be known as known. The internal combustion engine has at least one combustion chamber, in particular in the form of a cylinder, and an intake tract through which air can flow, by means of which the air is guided to the combustion chamber. This means that the air flowing through the intake tract can flow into the combustion chamber. The internal combustion engine further comprises at least one compressor arranged in the intake tract, by means of which the air to be supplied to the combustion chamber is compressed. The compression of the air and supplying the combustion chamber with the compressed air is also referred to as charging, so that the internal combustion engine is designed as a supercharged internal combustion engine or supercharged internal combustion engine. The compressed air is also referred to as charge air. Usually, the fuel chamber in addition to the air and fuel, in particular liquid fuel, fed, wherein the fuel and the air are combusted in the combustion chamber. Therefore, the air is also referred to as combustion air.

The internal combustion engine further comprises at least one intercooler, which is arranged in the intake tract downstream of the compressor. By means of the intercooler, the compressed by the compressor and thus heated air is cooled.

In addition, the disclosed DE 10 2012 207 903 A1 a device for obtaining water from an exhaust system of an internal combustion engine, in particular for a water injection system for the internal combustion engine, wherein a condenser is arranged for condensing a contained in an exhaust gas of the engine water vapor to liquid water in the exhaust system and wherein the water in a reservoir of the water injection system for Re-injection is collectable to a combustion process of the internal combustion engine. Furthermore, it is provided that the condenser is arranged in a muffler of the exhaust system.

In addition, the reveals DE 10 2012 207 904 A1 a method for suppressing pre-ignition occurring in a combustion chamber of an internal combustion engine before ignition, comprising the steps of: detecting the occurrence of or increasing the risk of pre-ignition and, depending thereon, injecting water or injecting water with changed injection characteristics.

Furthermore, it is known from the general state of the art to design internal combustion engines increasingly according to the so-called downsizing principle. As part of the downsizing, the stroke volume of the respective internal combustion engine is kept low. Nevertheless, in order to realize high specific powers and torques, the internal combustion engine is charged. This charging takes place for example by means of an exhaust gas turbocharger, which comprises the aforementioned compressor and a turbine. The turbine is arranged in an exhaust gas tract of the internal combustion engine and can be driven by the exhaust gas, wherein the compressor can be driven by the turbine. As a result, energy contained in the exhaust gas can be used to compress the air.

Due to the unbroken trend of downsizing to reduce CO ₂ emissions, the specific torque and specific performance of internal combustion engines, in particular gasoline engines, are steadily increasing. This is made possible inter alia by the supercharging of the internal combustion engine, which is equipped for example with a direct injection. In such a direct injection, the fuel is introduced directly into the combustion chamber, in particular injected.

In order to achieve a favorable efficiency - and thus a low fuel consumption - in turbocharged operation, the internal combustion engine should be operated with a favorable center of gravity. For this purpose, an effective cooling of the compressed air is of particular importance, which - due to the desire to increase the compression ratio with the aim of further improving fuel consumption - is becoming increasingly important.

Both with increasing specific torque and increasing specific power of the internal combustion engine as well as by increasing the compression ratio of the cooling demand of the compressed air continues to increase, resulting in that the intercooler is increased as of today. Both the available cooling capacity of a conventional intercooler and the installation space in the vehicle or in the motor vehicle are limited, which is why long-term alternative solutions for cooling the compressed air will be necessary.

In current internal combustion engines, in particular gasoline engines, the Intercooling by means of a charge air cooler, which is flowed through by the compressed air. By means of the charge air cooler heat is extracted from the compressed air. The heat is then released from the intercooler functioning as a heat exchanger or, for example, directly to the environment or to a coolant flowing through the intercooler, in particular a low-temperature circuit of the motor vehicle. It is therefore distinguished between the so-called direct and indirect charge air cooling. Depending on the design, one or more charge air coolers or heat exchangers through which the compressed combustion air can flow are used to cool the compressed air. This type of cooling is also known as active charge air cooling.

Object of the present invention is to provide an internal combustion engine of the type mentioned, in which the compressed air can be cooled particularly advantageous.

This object is achieved by an internal combustion engine having the features of patent claim 1. Advantageous embodiments with expedient developments of the invention are specified in the remaining claims.

To further develop an internal combustion engine specified in the preamble of claim 1 type such that the compressed air (charge air) can be cooled particularly advantageous, it is inventively provided that the charge air cooler is adapted to cause a condensation of water contained in the compressed air , wherein at least one container for receiving the condensed water and a supply means are provided, by means of which the condensed water from the container of the compressed air can be fed. In other words, the water is introduced into the compressed air, in particular injected into the compressed air. The water is used here as a cooling medium, by means of which the compressed air is removed by evaporation of the cooling medium heat. As a result, the compressed air can be cooled at least almost without pressure loss. By means of the feeder, it is thus possible to realize particularly demand-oriented cooling of the compressed air (charge air). In addition, a particularly efficient cooling of the charge air can be realized in the internal combustion engine according to the invention, since the already existing intercooler is not only used for cooling the compressed air, but also for the recovery of water from the compressed air. This gives the intercooler a dual function and synergy effects can be used.

Basically, the cooling of the compressed air by means of a cooling medium, which is supplied to the compressed air, the Mitfuhr a container in which the cooling medium is stored. Depending on the load spectrum, the cooling requirement and the operating strategy with regard to the supply of the cooling medium into the compressed air, there is a need for cooling medium. In order to avoid now to be performed by a user of the motor vehicle fillings or refueling of the container or to maximize time intervals between refueling of the container, the charge air cooler is used to recover the cooling medium in the form of water from the compressed air. In contrast to the extraction of water from exhaust gas of the internal combustion engine no additional capacitor is required in the internal combustion engine according to the invention, so that associated consequences such as a higher weight, a higher space requirement, a higher exhaust back pressure, etc. can be avoided.

In the internal combustion engine according to the invention, the intercooler thus represents a weight, cost and space neutral device for water extraction. In addition to cooling the compressed air, it is possible by supplying the water in the compressed air to keep the risk of knocking combustion particularly low. Furthermore, any pre-ignition may be prevented or reacted to any pre-ignition.

By means of the feeder, the water is for example injected directly into the combustion chamber and thereby fed to the compressed air. The compressed air is supplied to the water acting as a cooling medium, before the air is burned into the combustion chamber together with fuel. Alternatively or in addition to the direct introduction, in particular injection, of the water into the combustion chamber, it is conceivable for the compressed air to be supplied to the water at at least one point arranged upstream of the combustion chamber, in particular in the intake tract.

Further advantages, features and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. The features and combinations of features mentioned above in the description as well as the features and feature combinations mentioned below in the description of the figures and / or in the sole FIGURE are usable not only in the respectively indicated combination but also in other combinations or in isolation, without the To leave frame of the invention.

The drawing shows in the single FIGURE a schematic representation of an internal combustion engine for a motor vehicle, with a charge air cooler for cooling compressed air, wherein the charge air cooler is adapted to cause a condensation of water contained in the compressed air and at least one container for receiving the condensed water and a supply means are provided, by means of which the condensed water from the container of the compressed air can be fed.

The some Fig. Shows a schematic representation of an internal combustion engine 10 a motor vehicle, in particular a passenger car, which by means of the internal combustion engine 10 is drivable. The internal combustion engine 10 includes a cylinder housing 12 through which combustion chambers present in the form of cylinders 14 are formed. From the Fig. It can be seen that the internal combustion engine 10 in this case exactly four cylinders 14 which are arranged in series. Thus, the internal combustion engine 10 designed as a 4-cylinder in-line engine. The internal combustion engine 10 is operable with fuel in the form of liquid fuel which is in a fuel tank 16 is recorded or stored. To the cylinders 14 with the fuel from the fuel tank 16 to supply, includes the internal combustion engine 10 an injection system 18 , Here is the fuel tank 16 over a fuel line 20 with a fuel rail 22 the injection system 18 fluidly connected, leaving fuel from the fuel tank 16 the fuel rail 22 can be supplied.

Per cylinder 14 includes the internal combustion engine 10 an injection element in the form of an injector 26 by means of which the fuel directly into the respective cylinder 14 is injected. Thus, the internal combustion engine 10 equipped with a direct injection. From the Fig. It can be seen that the injectors 26 with the injectors 26 common fuel rail 22 are fluidically connected, so that the injectors with the in the fuel rail 22 absorbed fuel can be supplied. In other words, in the fuel rail 22 absorbed fuel by means of the fuel rail 22 on the injectors 26 Distributed so that the fuel at a high pressure, which is the fuel in the fuel rail 22 having, by means of the injectors 26 in the cylinders 14 can be injected directly.

The internal combustion engine 10 further comprises an air-flowable intake tract 28 in which a suction module 30 is arranged. For example, in its fired operation, the internal combustion engine sucks 10 Air from the environment, with the air according to a directional arrow 32 in the intake tract 28 flows. The intake tract 28 flowing air is through the intake 28 to the cylinders 14 guided, with the air the intake module 30 flows through. By means of the intake module 30 will be the intake module 30 flowing air on the cylinder 14 distributed so that the air from the intake module 30 in the cylinders 14 flows.

Thus, the cylinders 14 Supplied air and fuel, so that in the respective cylinders 14 a fuel-air mixture is formed. This fuel-air mixture is ignited, for example, by auto-ignition or spark ignition and thereby burned, whereby exhaust gas from the internal combustion engine 10 arises. The internal combustion engine 10 is designed for example as a gasoline engine. However, the previous and following embodiments can be easily transferred to other internal combustion engines.

The internal combustion engine 10 further comprises an exhaust tract through which the exhaust gas can flow 36 , by means of which the exhaust gas from the cylinders 14 is dissipated. Furthermore, the internal combustion engine comprises 10 at least one exhaust gas turbocharger 40 which is one in the exhaust tract 36 arranged and driven by the exhaust turbine 42 having. The turbine 42 comprises, for example, a turbine wheel which can be rotated about an axis of rotation and which can be driven by the exhaust gas. After driving the turbine 42 or the turbine wheel, the exhaust gas flows to an exhaust aftertreatment device 44 , which in the exhaust tract 36 downstream of the turbine 42 is arranged. By means of the exhaust aftertreatment device 44 the exhaust gas is cleaned before it according to a directional arrow 46 is released to the environment.

The turbocharger 40 also includes a wave 48 with which the turbine wheel is rotatably connected. In addition, the exhaust gas turbocharger includes 40 one in the intake tract 28 arranged compressor 50 which has a turbine wheel. By means of the compressor 50 or the turbine wheel is the the intake 28 compressed air flowing through. The compressor wheel is non-rotatable with the shaft 48 connected so that the compressor wheel over the shaft 48 is drivable by the turbine wheel. In other words, the compressor 50 from the turbine 42 drivable, so that energy contained in the exhaust gas can be used to compress the air.

By compressing the air, the air is heated. To represent a particularly high degree of supercharging, is in the intake 28 at least one intercooler 52 arranged. Based on the flow direction of the air through the intake tract 28 is the intercooler 52 downstream of the compressor 50 arranged so that the means of the compressor 50 compressed air by means of the intercooler 52 is cooled before the air in the cylinder 14 flows. Supplying the cylinders 14 with compressed air is also referred to as charging or charging, wherein the compressed air is also referred to as charge air. Because the air together with fuel in the cylinders 14 is burned, the air is also referred to as combustion air. The intercooler 52 is for example a heat exchanger and acts as a cooling device by means of which the charge air is cooled.

In this case, an indirect charge air cooling can be provided. This indirect intercooler is the intercooler 52 by a coolant, in particular a cooling liquid, flows through, wherein said coolant is a so-called low-temperature circuit of the internal combustion engine 10 flows through. As a result of heat transfer from the charge air via the intercooler 52 to the coolant, the charge air is cooled. This low-temperature circuit may be equipped, for example, by a heat exchanger for heat transfer to a chiller in order to increase the cooling effect significantly by means of the so-called active charge air cooling.

In the embodiment illustrated in the figure, however, direct charge air cooling is provided. In this direct intercooling is working on the principle of a thermodynamic cycle processor chiller 58 provided with a cycle passing through the refrigerant. This refrigerant flows through a refrigerant circuit of the refrigerator 58 , where the intercooler 52 is arranged in the refrigerant circuit. Thus, the refrigerant flows through the intercooler 52 , so that the charge air as a result of heat transfer from the charge air via the intercooler 52 to the intercooler 52 flowing refrigerant particularly effective, that is strong, can be cooled. Here is the chiller 58 for example, designed as a compression refrigeration machine.

Preferably, the chiller 58 a refrigerator of an air conditioner for supplying the interior of the motor vehicle with conditioned air. Thus comes the chiller 58 or the refrigerant to a dual function, since the chiller 58 or the refrigerant is used on the one hand to cool the air to be supplied to the interior. The other is the chiller 58 or the refrigerant used to charge the charge air via the intercooler 52 to cool.

To realize a particularly efficient and advantageous cooling of the charge air, is the intercooler 52 designed to cause a condensation of water contained in the compressed air. Furthermore, at least one container 56 provided for receiving the condensed water. From the Fig. It can be seen that the intercooler 52 over at least one line 60 with the container 56 is fluidically connected. By means of the line 60 this is done by means of the intercooler 52 condensed water from the intercooler 52 discharged and to the container 56 or in the container 56 guided so that the condensed water in the container 56 can be stored.

In addition, the internal combustion engine includes a whole 62 designated feeder, by means of which the condensed water from the container 56 the compressed air is supplied or is supplied. In the present case, the feed device comprises 62 Injectors 54 , by means of which the condensed water from the container 56 directly into the cylinder 14 is injectable or injected. This means that already in the cylinder 14 incoming charge air by means of the feeder 62 and in particular by means of the injection valves 54 with the water from the container 56 is applied before the charge air in the cylinders 14 is burned. These are the injectors 54 with the container 56 fluidly connected, so that the condensed water from the container 56 to the injectors 54 can be performed. In other words, in the embodiment illustrated in the figure, a direct injection or direct injection of the water acting as a cooling medium is provided, wherein the water directly into the cylinder 14 introduced, in particular injected, is. This means that at least one point at which the water acting as the cooling medium can be supplied to the air or is supplied in the respective cylinder 14 is arranged.

Alternatively or additionally, it is conceivable that at least one point at which the water can be supplied to the air or is supplied upstream of the cylinder 14 is arranged. For example, the water from the container 56 at one on the intake module 30 arranged location of the compressed air to be supplied. Preferably, it is provided that the at least one point at which the compressed air, the water from the container 56 is fed, downstream of the intercooler 52 is arranged to thereby realize a particularly effective and strong cooling.

The intercooler 52 is thus used as a device for recovering water from the combustion air. By means of the intercooler 52 a heat removal is effected by the compressed air. By Using the active intercooling, a particularly effective heat dissipation can be realized, so that a particularly high amount of heat can be dissipated by the charge air. This heat dissipation has a condensation of the water connecting in the combustion air result. The condensed water is passed through the line 60 to the container 56 guided and stored there. Thus, a particularly needs-based supply of water acting as a cooling medium in the compressed air can take place.

By combining the supply of water in the compressed air with the active charge air cooling a particularly large amount of condensed and thus recoverable water can be realized, which significantly increases the efficiency of the intercooler by injecting the water. The reasons for this are: with a high degree of supercharging very high air mass flow and thus high water mass flow, which can be used for water production. High temperature gradient between combustion air and wall temperature inside the heat exchanger. Injection of a cooling medium in the form of water allows further increase in the degree of supercharging.

By using the intercooler 52 for intercooling and for water production, no additional condenser for water production is required. By introducing the water into the combustion air, the oxygen density in the combustion air can be increased. By passing the condensed water into the container 56 may be the reservoir acting as a reservoir 56 be filled or refilled, so that, for example, particularly long time intervals between each manual refill of the container 56 can be realized.

Furthermore, it is possible the size of the container 56 (Reservoir) to keep particularly low, so that the space requirement of the internal combustion engine 10 can be kept low. The risk of incorrect refueling of the container 56 can be avoided or kept very low. Furthermore, particularly large amounts of water or cooling medium are available, whereby the map area, in which water is injected into the combustion air, can be extended. In addition, synergy effects can be realized when using the active intercooler. Furthermore, a more favorable design of the internal combustion engine 10 possible, in particular in the form of a higher compression ratio of an increased power or an increased torque and a reduced fuel consumption. In addition, the introduction represents an enormous potential for reducing fuel consumption and CO ₂ emissions through further downsizing.

LIST OF REFERENCE NUMBERS

10

Internal combustion engine

12

cylinder housing

14

cylinder

16

Fuel tank

18

injection

20

Fuel line

22

Fuel rail

26

injector

28

intake system

30

Intake module

32

arrow

36

exhaust tract

40

turbocharger

42

turbine

44

exhaust treatment device

46

arrow

48

wave

50

compressor

52

Intercooler

54

Injector

56

container

58

refrigeration machine

60

management

62

feeding

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102007045347 A1 [0002]
• DE 102012207903 A1 [0004]
• DE 102012207904 A1 [0005]

Claims (7)

Internal combustion engine ( 10 ) for a motor vehicle, with at least one combustion chamber ( 14 ), with one of the combustion chamber ( 14 ) air to be supplied through the intake tract ( 28 ), with at least one in the intake tract ( 28 ) arranged compressors ( 50 ) for compressing the combustion chamber ( 14 ) and at least one in the intake tract ( 28 ) downstream of the compressor ( 50 ) arranged intercooler ( 52 ) for cooling the compressed air, characterized in that the intercooler ( 52 ) is adapted to cause a condensation of water contained in the compressed air, wherein at least one container ( 56 ) for receiving the condensed water and a feeder ( 62 ) are provided, by means of which the condensed water from the container ( 56 ) of the compressed air can be supplied. Internal combustion engine ( 10 ) according to claim 1, characterized in that a working on the principle of a thermodynamic cycle chiller ( 58 ) with a continuous cycle and the intercooler ( 52 ) is provided by means of which the compressed air via the intercooler ( 52 ) is to cool. Internal combustion engine ( 10 ) according to claim 2, characterized in that the chiller ( 58 ) a chiller ( 58 ) is an air conditioner for supplying the interior of the motor vehicle with conditioned air. Internal combustion engine ( 10 ) According to one of the preceding claims, characterized in that the charge air cooler ( 52 ) with a flow-through of a coolant low-temperature circuit of the internal combustion engine ( 10 ) and for the cooling of the compressed air can be flowed through by the coolant. Internal combustion engine ( 10 ) according to one of the preceding claims, characterized in that at least one point at which the water can be supplied to the air, in the combustion chamber ( 14 ) is arranged. Internal combustion engine ( 10 ) according to one of the preceding claims, characterized in that at least one point at which the water can be supplied to the air, upstream of the combustion chamber ( 14 ) is arranged. Method for operating an internal combustion engine ( 10 ) according to any one of the preceding claims.

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