Internal combustion engine, method for operating the same and control device for carrying out the method

Patent metadata

Field	Value
Publication number	US-10094270-B2
Application number	US-201615019511-A
Country	US
Kind code	B2
Filing date	Feb 9, 2016
Priority date	Feb 10, 2015
Publication date	Oct 9, 2018
Grant date	Oct 9, 2018

Abstract

An internal combustion engine includes: plural cylinders, a first exhaust gas turbocharger having a high-pressure turbine and a high-pressure compressor, a second exhaust gas turbocharger having a low-pressure turbine and a low-pressure compressor, and an SCR catalytic converter positioned between the high-pressure turbine and the low-pressure turbine, via which exhaust gas leaving the high-pressure turbine is conducted upstream of the low-pressure turbine. The low-pressure compressor is assigned a power take-in, via which the low-pressure compressor can be driven when as a consequence of a relatively large exhaust gas temperature drop at the SCR catalytic converter via the low-pressure turbine an adequate amount of energy required to supply the cylinders of the internal combustion engine with a desired quantity of charge air can no longer be provided.

First claim

What is claimed is:

1. An internal combustion engine ( 10 ) comprising:
a plurality of cylinders ( 11 ), the cylinders producing exhaust gas ( 12 );
a first exhaust gas turbocharger ( 14 a ) including a high-pressure turbine ( 13 a ) and a high-pressure compressor ( 16 a );
a second exhaust gas turbocharger ( 14 b ) including a low-pressure turbine ( 13 b ) and a low-pressure compressor ( 16 b );
at least one exhaust gas aftertreatment device positioned between the high-pressure turbine ( 13 a ) and the low-pressure turbine ( 13 b ), the at least one exhaust gas aftertreatment device being at least one selected from the group of: a particle filter, a CO oxidation catalytic converter, CH 2 O oxidation catalytic converter, a CH 4 oxidation catalytic converter, and an SCR catalytic converter ( 17 ), the at least one exhaust gas aftertreatment device conducting all of the exhaust gas ( 12 ) produced by the cylinders ( 11 ), including any exhaust gas ( 12 ) leaving the high-pressure turbine ( 13 a ), downstream to the low-pressure turbine ( 13 b );
a first temperature sensor ( 18 ) arranged downstream of the high-pressure turbine ( 13 a ) and upstream of the at least one exhaust gas aftertreatment device;
a second temperature sensor ( 19 ) arranged downstream of the at least one exhaust gas aftertreatment device and upstream of the low-pressure turbine ( 13 a );
a power take-in ( 21 ) coupled to the low-pressure compressor ( 16 b ), the power take-in ( 21 ) being configured to provide extra energy to the low-pressure compressor ( 16 b ) in a case in which an exhaust gas temperature drop greater than a threshold amount occurs at the at least one exhaust gas aftertreatment device; and
a control device ( 20 ) configured to automatically determine and automatically adjust, based on a temperature difference between the temperature of the exhaust gas ( 12 ) measured at the first temperature sensor ( 18 ) and the temperature of the exhaust gas ( 12 ) measured at the second temperature sensor ( 19 ), the amount of extra energy provided at the power take-in ( 21 ) for driving the low-pressure compressor ( 16 b ), such that the greater the temperature drop and thus the energy loss along the at least one exhaust gas aftertreatment device, the more energy is fed to the power take-in ( 21 ) and thus to the low-pressure compressor ( 16 b ), so as to supply the cylinders ( 11 ) of the internal combustion engine ( 10 ) with an adequate amount of charge air.

2. The internal combustion engine according to claim 1 , further comprising a power take-out, coupled to the high-pressure turbine ( 13 a ), the power take-out ( 24 ) being configured to extract energy at the high-pressure turbine ( 13 a ) for driving the low-pressure compressor ( 16 b ).

3. The internal combustion engine according to claim 1 , wherein the power take-in ( 21 ) comprises an electric motor.

4. The internal combustion engine according to claim 2 , wherein the power take-out ( 24 ) comprises an electric machine having a generator that is configured to, when the high-pressure turbine ( 13 a ) provides more than a threshold amount of energy to the high-pressure compressor ( 16 a ), convert the excess energy into electric energy, wherein the electric energy is directly utilizable for driving the power take-in ( 21 ) and the low-pressure compressor ( 16 b ), and wherein the electric energy is utilizable to charge an electric energy storage unit.

5. The internal combustion engine according to claim 2 , wherein the power take-out ( 24 ) is mechanically coupled to the power take-in ( 21 ).

6. A method for operating an internal combustion engine ( 10 ) having a plurality of cylinders ( 11 ), the cylinders producing exhaust gas ( 12 ), a first exhaust gas turbocharger ( 14 a ) including a high-pressure turbine ( 13 a ) and a high-pressure compressor ( 16 a ), a second exhaust gas turbocharger ( 14 b ) including a low-pressure turbine ( 13 b ) and a low-pressure compressor ( 16 b ), at least one exhaust gas aftertreatment device positioned between the high-pressure turbine ( 13 a ) and the low-pressure turbine ( 13 b ), the at least one exhaust gas aftertreatment device being at least one selected from the group of: a particle filter, a CO oxidation catalytic converter, CH 2 O oxidation catalytic converter, a CH 4 oxidation catalytic converter, and an SCR catalytic converter ( 17 ), the at least one exhaust gas aftertreatment device conducting all of the exhaust gas ( 12 ), produced by the cylinders ( 11 ), including any exhaust gas ( 12 ) leaving the high-pressure turbine ( 13 a ), downstream to the low-pressure turbine ( 13 b ), and a power take-in ( 21 ) coupled to the low-pressure compressor ( 16 b ), the method comprising:
driving, with the power take-in ( 21 ), by providing extra energy to the low-pressure compressor ( 16 b ) in a case in which and exhaust gas temperature drop greater than a threshold amount occurs at the at least one exhaust gas aftertreatment device;
determining exhaust gas temperatures with a first temperature sensor ( 18 ) positioned downstream of the high-pressure turbine ( 13 a ) and upstream of the at least one exhaust gas aftertreatment device and with a second temperature sensor ( 19 ) positioned downstream of the at least one exhaust gas aftertreatment device and upstream of the low-pressure turbine ( 13 a ); and
depending upon a temperature difference between the temperature of the exhaust gas ( 12 ) at the first temperature sensor ( 18 ) and the temperature of the exhaust gas ( 12 ) at the second temperature sensor ( 19 ), automatically determining and automatically adjusting the amount of extra energy to be provided at the power take-in ( 21 ) for driving the low-pressure compressor ( 16 b ), such that the greater the temperature drop and thus the energy loss along the at least one exhaust gas aftertreatment device, the more energy is fed to the power take-in ( 21 ) and thus to the low-pressure compressor ( 16 b ), so as to supply the cylinders ( 11 ) of the internal combustion engine ( 10 ) with an adequate amount of charge air.

7. The method according to claim 6 , wherein at the high-pressure turbine ( 13 a ) energy for driving the power take-in ( 21 ) is extracted via a power take-out ( 24 ).

8. A control device ( 20 ) of an internal combustion engine ( 10 ), the control device ( 20 ) being configured to carry out the method according to claim 6 .

Assignees

• Man Diesel & Turbo Se
• Man Energy Solutions Se

Inventors

• Döring Andreas
• Maier Julia

Classifications

• F02B37/10 Primary

  at least one pump being alternatively {or simultaneously} driven by exhaust and other drive, {e.g. by pressurised fluid from a reservoir or an engine-driven pump} · CPC title

• F01N3/103

  Oxidation catalysts for HC and CO only · CPC title

• F02B75/18

  Multi-cylinder engines (scavenging aspects F02B25/00) · CPC title

• F02B39/10

  electric · CPC title

• F01N5/04

  the devices using kinetic energy · CPC title