DE102009047355A1 - Combustion engine has compressor with compressor outlet opening and cylinder with cylinder inlet opening, where compressor outlet opening is connected with cylinder inlet opening in aerodynamic manner - Google Patents

Abstract

The combustion engine has a compressor (1) with a compressor outlet opening and a cylinder (4) with a cylinder inlet opening, where the compressor outlet opening is connected with the cylinder inlet opening in an aerodynamic manner. A gas storage chamber is arranged with a variable volume between the compressor outlet opening and the cylinder inlet opening. An independent claim is also included for a method for operating a combustion engine.

Description

The present invention relates to an internal combustion engine and a method of operating an internal combustion engine.

A major limitation in the implementation of currently used turbocharger acceleration concepts for internal combustion engines, such as engines, represents the pressure ratio in the compressor. This pressure ratio in the compressor must not exceed a certain limit. For this reason, it is necessary that at high exhaust gas temperatures, a part of the heat of the exhaust gas remains unused. For example, a portion of the hot exhaust gas bypasses the turbine via a bypass passage, or in the case of a variable turbine geometry, the turbine blades are opened. The disadvantage of this is a loss of thermal energy of the exhaust gas. The thermal energy could otherwise have been converted to mechanical energy, for example with the aid of a turbocharger, thereby contributing to a reduction in fuel consumption.

There is therefore a need for a solution which is independent of a restriction by the pressure ratio in the compressor and which allows maximum conversion of the thermal energy of the exhaust gas into mechanical energy.

In WO 2004/025097 A1 An internal combustion engine, in particular a motor vehicle, is described. The internal combustion engine includes a compressor, an exhaust gas turbocharger, a compressor bridging the air passage and a compression throttle. As soon as the mass flow, which the exhaust gas turbocharger is able to convey due to an exhaust gas mass flow, exceeds the delivery volume of the compressor, part of the mass flow is conducted past the compressor through the air passage bridging the compressor.

In DE 101 58 874 A1 an exhaust gas turbocharger for an internal combustion engine is disclosed, which includes a the compressor region associated additional air supply device with an additional air duct in the compressor housing for the supply of additional air. In particular, an annular space is provided which serves as a collecting space for the introduced into the compressor housing additional air. The annulus acts pressure surge compensating, whereby an additional supply of additional air is ensured with uniform pressure. For example, it may be appropriate to feed additional air downstream of the supercharging speed threshold directly into the intake tract downstream of the compressor (compressor) in order in this way to ensure increased charge pressure. In particular, it is a matter of balancing a more or less pronounced torque weakness in internal combustion engines with exhaust gas turbochargers in the lower engine speed range.

A similar device is in DE 103 61 913 A1 described. In the process, the torque weakness due to insufficient charging of the motors in the lower speed range is also compensated by charging with air from a reservoir.

Furthermore, in DE 199 44 946 A1 and in DE 10 2007 059 145 A1 Internal combustion engines with a compressed air reservoir or pressure vessel for additional supply of the respective turbo-charged internal combustion engine with compressed air disclosed. The additional supply of compressed air from the pressure vessel or the compressed air reservoir serves to equalize the charge pressure in supercharged internal combustion engines, in particular internal combustion engines.

In EP 0 754 843 B1 An internal combustion engine with turbocharger and a method for accelerating the exhaust gas turbocharger of an internal combustion engine will be described. In this case, part of the gas stream is transferred from the combustion chamber into a pressure accumulator and later fed to the turbine wheel of the exhaust gas turbocharger.

In EP 1 489 289 A3 a method for low-particle operation of a diesel engine and a low-particle diesel engine is described, with the introduction of an acceleration process additional charge air is introduced.

In WO 03/0044348 A1 A method is described for changing the charge in a piston-type internal combustion engine and for carrying out the method-suitable charge exchange system. In this case, the combustion chamber is optionally supplied with charge air via a compressor branch or via a suction air branch, which bypasses the compressor bypass supplied.

In the cited prior art, the acceleration control is limited by the restriction of the pressure ratio in the compressor required to protect the compressor. This is especially true at high temperatures of the exhaust gas.

Against this background, it is a first object of the present invention to provide an advantageous combustion engine. A second object is to provide an advantageous method for operating an internal combustion engine.

The first object is achieved by an internal combustion engine according to claim 1. The second object is achieved by a method for operating an internal combustion engine according to claim 7. The dependent claims contain further, advantageous embodiments of the invention.

The internal combustion engine according to the invention comprises a compressor with a compressor outlet opening and at least one cylinder with a cylinder inlet opening. The Kompressorauslaßöffnung is fluidically connected to the cylinder inlet opening. The internal combustion engine further includes at least one variable volume gas storage space disposed between the compressor discharge port and the cylinder intake port.

Typically, the internal combustion engine according to the invention may comprise a plurality of cylinders, in particular 4, 6, 8 or 12 cylinders. However, an odd number of cylinders may also be present, for example the internal combustion engine according to the invention may comprise 5 cylinders. Advantageously, a suction chamber (plenum chamber) is connected upstream of the cylinder or cylinders. The suction chamber may be configured, for example, as a gas storage space with a variable volume. In particular, the suction chamber may be identical to the gas storage space having a variable volume described above.

The internal combustion engine according to the invention may further comprise a turbocharger. In this case, the compressor may be a turbocharger compressor.

By the gas storage room with variable volume, the above-mentioned restrictions for the protection of the compressor can be avoided or make them irrelevant for the operation of the internal combustion engine. In particular, the volume of the gas storage space can be varied so that the pressure ratio in the compressor does not exceed a certain, predetermined value or is kept constant within a certain range.

Furthermore, a throttle valve and / or a radiator may be arranged between the compressor outlet opening and the cylinder inlet opening. The cooler may be, for example, a charge air cooler. The gas storage space may be disposed between the compressor discharge port and the radiator or between the radiator and the cylinder intake port. Alternatively, the radiator may include the gas storage space. This means that the gas storage room can be integrated into the cooler.

In addition, the internal combustion engine may include an exhaust gas recirculation system and / or a turbine. The turbine may be, for example, a turbocharger turbine. The exhaust gas recirculation system may in particular comprise a cooler for cooling the exhaust gas to be recirculated.

In addition, the internal combustion engine may include a turbine, in particular a turbocharger turbine, and a bypass flow channel. In this case, the bypass flow channel can connect the gas storage space with a fluid flow channel arranged downstream of the turbine. In this way, unneeded gas from the gas storage space can be admixed with the exhaust gas emitted by the turbine. The gas that is not needed can be routed past the cylinder and the turbine. The gas may be air or a mixture of air and exhaust gas.

With the help of the internal combustion engine according to the invention, the compressor can effectively protect against overload. At the same time, the thermal energy of the exhaust gas can be effectively utilized.

The method of operating an internal combustion engine according to the invention relates to an internal combustion engine comprising a compressor and at least one cylinder. In the context of the method according to the invention, the volume of a gas storage space arranged between the compressor and the cylinder in terms of flow is varied as a function of the operating state of the internal combustion engine. The inventive method can be carried out in particular with the aid of the internal combustion engine according to the invention.

For example, the internal combustion engine may include a turbocharger. In this case, the compressor may be a turbocharger compressor.

Advantageously, the volume of the gas storage space can be varied as a function of the rotational speed and / or the torque of the internal combustion engine. Furthermore, the volume of the gas storage space can be varied depending on other load parameters of the internal combustion engine.

The internal combustion engine may also include a plurality of variable volume gas storage spaces. The internal combustion engine may be, for example, an engine, in particular a diesel engine.

Furthermore, a gas can be introduced from the compressor into the gas storage space and then forwarded to the cylinder, wherein the gas is cooled. In this case, the gas can be cooled after leaving the compressor and before being introduced into the gas storage space. However, the gas can also be cooled after leaving the gas storage space and before it is introduced into the cylinder. Another alternative is that the gas is cooled within a cooler comprising the variable volume gas storage space.

Preferably, the volume of the gas storage space is varied so that the pressure ratio in the compressor is kept constant. In particular, the volume of the gas storage space can be increased upon reaching acceleration values of the internal combustion engine above a predetermined limit value. Advantageously, the volume of the gas storage space can be varied, in particular possibly increased, such that a maximum compressor thrust value is not reached.

Furthermore, exhaust gas may be recirculated from an outlet port of the cylinder to an inlet port of the cylinder and / or to an inlet port of the compressor. In the latter case, a mixture of air and exhaust gas is compressed in the compressor.

In principle, the gas stored in or introduced into the gas storage space can be air or a mixture of air and exhaust gas.

The internal combustion engine may include a turbine and a bypass flow channel. In this case, the bypass flow channel can connect the gas storage space with a fluid flow channel arranged downstream of the turbine. The stored gas in the gas storage space can be introduced into the cylinder. Alternatively, the gas stored in the gas storage space may be introduced through the bypass flow channel into the flow channel located downstream of the turbine. In the latter case, the gas is conducted past the cylinder and the turbine. The turbine may in particular be a turbocharger turbine. The gas leaving the turbine and / or the gas bypassing the turbine via the bypass flow channel can then be routed further to at least one exhaust aftertreatment component.

Further features, features and advantages of the present invention will be explained in more detail below with reference to an embodiment with reference to the accompanying figures. The features described are advantageous both individually and in combination with each other.

1 schematically shows the structure of a conventional internal combustion engine.

2 schematically shows the structure of a first variant of an internal combustion engine according to the invention.

3 schematically shows the structure of a second variant of an internal combustion engine according to the invention.

4 schematically shows the structure of a third variant of an internal combustion engine according to the invention.

In the following, an embodiment of the present invention will be described with reference to FIGS 1 to 4 explained in more detail. The 1 schematically shows the structure of a conventional internal combustion engine. The internal combustion engine includes a compressor 1 , a cooler 2 , a cylinder 4 , a turbine 5 and an automatic transmission 6 , The compressor 1 and the turbine 5 may be components of a turbocharger.

In the flow direction 15 the intake air is connected to the compressor 1 the cooler 2 arranged. The intake air is in the flow direction 15 from the radiator 2 to the cylinder 4 forwarded. Between the radiator 2 and the cylinder 4 is a throttle valve 3 arranged, through which the intake air is passed through. In the cylinder 4 The intake air is burned together with a fuel to hot exhaust gas. The hot exhaust gas is in the flow direction 16 in the turbine 5 initiated. The generated mechanical energy is transferred to the automatic transmission 6 transfer.

The internal combustion engine further comprises an exhaust gas recirculation system including an exhaust gas recirculation device 8th and a cooler 7 umfallt. Part of the cylinder 4 leaving exhaust gas is in the flow direction 17 to the radiator 7 directed and from there the exhaust gas recirculation device 8th fed. After leaving the exhaust gas recirculation device 8th the recirculated exhaust gas is returned to the cylinder 4 initiated.

The 2 schematically shows the structure of a first variant of an internal combustion engine according to the invention. This includes the compressor 1 , which may be a turbocharger compressor, is a compressor discharge port 11 , The cylinder 4 includes a cylinder inlet opening 14 , Unlike the one in the 1 example shown is in the 2 between the compressor 1 and the radiator 2 a gas storage room 9 With arranged variable volume. The volume of the gas storage room 9 can be increased or decreased, for example, depending on the operating condition, in particular speed and torque of the internal combustion engine.

That's the compressor 1 through the compressor outlet 11 leaving gas is first in the gas storage room 9 initiated. Then this becomes the gas storage room 9 leaving gas to the radiator 2 fed. The flow direction of the gas is indicated by arrows 15 characterized.

In addition, the internal combustion engine according to the invention, a bypass flow channel 13 include, the fluidically the gas storage space 9 with a turbine 5 leaving flow channel 12 combines. At the flow channel 12 in particular, it may be an exhaust gas outlet duct of the turbine 5 act.

The 3 shows a second variant of an internal combustion engine according to the invention. Unlike the one in the 2 example shown is in the 3 the gas storage room 9 between the radiator 2 and the throttle valve 3 arranged. The gas storage room 9 is thus in the flow direction 15 the radiator 2 downstream.

A third embodiment variant of an internal combustion engine according to the invention is in the 4 shown schematically. The in the 4 The internal combustion engine shown comprises a radiator 10 , in which a gas storage room with variable volume is integrated. The cooler 10 with the integrated gas storage room with variable volume is between the compressor 1 , in particular the Kompressorauslaßöffnung 11 , and the cylinder 4 , in particular the cylinder inlet opening 14 arranged. The volume of the gas storage space can be increased or decreased, for example, as a function of load parameters, such as engine speed and torque, of the internal combustion engine.

To the in the cooler 10 integrated gas storage room with variable volume can turn a bypass flow channel 13 be connected, as described in the previous embodiments, in a turbine 5 leaving flow channel 12 opens. In addition, is again between the radiator 10 with integrated gas storage room and the cylinder 4 a throttle valve 3 ,

Basically, it can be in all variants of the compressor 1 and the turbine 5 to act components of a turbocharger. Furthermore, in all variants of the gas storage space 9 , or in the cooler 10 integrated gas storage space be designed so that at low compressor pressure, the volume of the gas storage space 9 is kept constant and accelerates the internal combustion engine in a conventional manner. In the case of high thermal energy of the exhaust gas is through the exhaust gas turbine 5 The mechanical energy generated mainly for the intake manifold of the compressor 1 to accelerate. For accelerations higher than a predetermined limit value, the volume of the gas storage space can be increased. In this way, the pressure ratio in the compressor 1 kept constant and avoided reaching the limit for the compressor thrust.

The procedure described has the following advantages: At low load, where a high exhaust gas recirculation is required for emission reduction, the volume upstream of the throttle valve 3 increase. In this case, under these conditions, the throttle valve 3 partly kept closed. This reduces the supply of fresh air upstream of the valve. Here, the power is limited by the thermal energy of the exhaust gas, which is too low in conventional combustion to achieve significant accelerations. On the other hand, high exhaust gas temperatures can be effectively utilized by the present invention, particularly during regeneration of the exhaust aftertreatment system, for example diesel particulate filter regeneration or purge of a catalyst. In particular, if necessary, an improvement in acceleration can be achieved.

In high load operating conditions, the thermal energy of the exhaust gas can be effectively utilized since no unused exhaust of hot exhaust gas is required due to compressor-related limitations, particularly limitations due to the occurrence of too high a pressure ratio.

Furthermore, in the context of exhaust gas recirculation, the exhaust gas can also be upstream of the compressor 1 be fed back to the compressor. In this case, the compressor is 1 and then the gas storage room 9 , or the gas storage room 9 comprehensive radiator 10 supplied a gas comprising air and exhaust gas. This mixture of air and exhaust gas is then available for low-load operating conditions.

In the case of extended volume operation, that is, the variable volume of the gas storage space 9 increased, the stored gas can either directly to the cylinder 4 be passed or through the bypass flow channel 13 a flow channel 12 that is downstream to the turbine 5 followed, initiated. In particular, it can be connected to the turbine 5 downstream flow channel 12 be arranged upstream of exhaust aftertreatment components. The amount of over the bypass flow channel 13 derived gas can be made dependent on the extent of exhaust gas recirculation.

LIST OF REFERENCE NUMBERS

1

compressor

2

cooler

3

throttle valve

4

cylinder

5

turbine

6

automatic drive

7

cooler

8th

Exhaust gas recirculation device

9

Gas storage room with variable volume

10

Cooler with integrated gas storage room with variable volume

11

Kompressorauslaßöffnung

12

flow channel

13

Bypass flow channel

14

Cylinder inlet port

15

flow direction

16

flow direction

17

flow direction

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

• WO 2004/025097 A1 [0004]
• DE 10158874 A1 [0005]
• DE 10361913 A1 [0006]
• DE 19944946 A1 [0007]
• DE 102007059145 A1 [0007]
• EP 0754843 B1 [0008]
• EP 1489289 A3 [0009]
• WO 03/0044348 A1 [0010]

Claims (15)

Internal combustion engine, which is a compressor ( 1 ) with a compressor outlet ( 11 ) and at least one cylinder ( 4 ) with a cylinder inlet opening ( 14 ), wherein the compressor outlet opening ( 11 ) fluidically with the cylinder inlet opening ( 14 ), characterized in that at least one gas storage space ( 9 ) with a variable volume between the compressor outlet ( 11 ) and the cylinder inlet opening ( 14 ) is arranged. Combustion engine according to claim 1, characterized in that between the compressor outlet ( 11 ) and the cylinder inlet opening ( 14 ) a throttle valve ( 3 ) and / or a cooler ( 2 ) is arranged. Combustion engine according to claim 2, characterized in that the gas storage space ( 9 ) between the compressor outlet ( 11 ) and the radiator ( 2 ) or between the radiator ( 2 ) and the cylinder inlet opening ( 14 ) is arranged. Combustion engine according to claim 2, characterized in that the radiator ( 2 . 10 ) the gas storage space ( 9 ). Combustion engine according to one of claims 1 to 4, characterized in that the internal combustion engine an exhaust gas recirculation system and / or a turbine ( 5 ). Combustion engine according to one of claims 1 to 5, characterized in that the internal combustion engine is a turbine ( 5 ) and a bypass flow channel ( 13 ), wherein the bypass flow channel ( 13 ) the gas storage space ( 9 ) with a downstream of the turbine ( 5 ) arranged flow channel ( 12 ) fluidically connects. Method for operating an internal combustion engine, comprising a compressor ( 1 ) and at least one cylinder ( 4 ), characterized in that the volume of a fluidically between the compressor ( 1 ) and the cylinder ( 4 ) arranged gas storage space ( 9 ) is varied depending on the operating state of the internal combustion engine. Method according to claim 7, characterized in that the volume of the gas storage space ( 9 ) is varied depending on the speed and / or the torque of the internal combustion engine. A method according to claim 7 or 8, characterized in that a gas from the compressor ( 1 ) into the gas storage room ( 9 ) and then to the cylinder ( 4 ) is passed, wherein the gas is cooled. A method according to claim 9, characterized in that the gas after leaving the compressor ( 1 ) and before entering the gas storage space ( 9 ) is cooled and / or after leaving the gas storage room ( 9 ) and before entering the cylinder ( 4 ) is cooled and / or inside a cooler ( 10 ), which includes the gas storage room of variable volume, is cooled. Method according to one of claims 7 to 10, characterized in that the volume of the gas storage space ( 9 ) is varied so that the pressure ratio in the compressor ( 1 ) is kept constant. Method according to one of claims 7 to 11, characterized in that the volume of the gas storage space ( 9 ) is increased when reaching acceleration values of the internal combustion engine above a predetermined limit value. Method according to one of claims 7 to 12, characterized in that the volume of the gas storage space ( 9 ) is varied so that a maximum compressor thrust value is not reached. Method according to one of claims 7 to 13, characterized in that the exhaust gas from an outlet opening of the cylinder ( 4 ) to an inlet opening ( 14 ) of the cylinder ( 4 ) and / or to an inlet opening of the compressor ( 1 ) is returned. Method according to one of claims 7 to 14, characterized in that the internal combustion engine is a turbine ( 5 ) and a bypass flow channel ( 13 ), which stores the gas storage space ( 9 ) with a downstream of the turbine ( 5 ) arranged flow channel ( 12 ) fluidically connects, and in the gas storage space ( 9 ) stored gas in the cylinder ( 4 ) or through the bypass flow channel ( 13 ) in the downstream of the turbine ( 5 ) arranged flow channel ( 12 ) is initiated.

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