Method for operating an internal combustion engine for favorable exhaust gas treatment

• US 9,464,587 B2
• Filed: 02/21/2013
• Issued: 10/11/2016
• Est. Priority Date: 03/01/2012
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hammer, Andreas, Zink, Oliver
• Primary Examiner(s): Low, Lindsay
• Assistant Examiner(s): JIN, GEORGE C.
• Application Number:
  US13/772,466
• Publication Number:
  US 20130231842A1
• Time in Patent Office: 1,328 Days
• Field of Search: 602/85, 180/65.28, 180/65.285, 180/65.265
• US Class Current: 1/1
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/16 for reducing engine exhaust emissions
• CPC Class Codes: B60W 2510/06 Combustion engines, Gas turbines
• CPC Class Codes: B60W 2510/0638 Engine speed
• CPC Class Codes: B60W 2510/068 Engine exhaust temperature
• CPC Class Codes: B60W 30/1882 characterised by the working point of the engine, e.g. by using engine output chart
• CPC Class Codes: F01N 2900/1402 Exhaust gas composition
• CPC Class Codes: F01N 3/208 Control of selective catalytic reduction [SCR], e.g. dosing of reducing agent
• CPC Class Codes: F02D 2200/0802 Temperature of the exhaust gas treatment apparatus
• CPC Class Codes: F02D 2250/24 by using an external load, e.g. a generator
• CPC Class Codes: F02D 41/0235 in relation with the state of the exhaust gas treating apparatus control of exhaust gas treating apparatus per se F01N
• CPC Class Codes: F02D 41/1445 the characteristics being related to the exhaust flow
• CPC Class Codes: F02D 41/1446 the characteristics being exhaust temperatures
• CPC Class Codes: F02D 41/146 the characteristics being an NOx content or concentration
• CPC Class Codes: F02D 41/1463 of the exhaust gases downstream of exhaust gas treatment apparatus
• CPC Class Codes: Y02A 50/20 Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y10S 903/902 : Prime movers comprising electrical and internal combustion motors

Abstract

The invention discloses a method for operating a drive device (10), in particular in a motor vehicle, comprising an internal combustion engine (12) and at least one further drive assembly (28) which is not an internal combustion engine (12), wherein an exhaust gas from the internal combustion engine (12) is treated by means of an exhaust gas treatment system (16), and wherein it is checked whether the internal combustion engine (12) is in an operating point defined as favorable for the exhaust gas treatment, and wherein then if it is found that the internal combustion engine (12) is not in an operating point defined as favorable for the exhaust gas treatment, the operating point of the internal combustion engine (12) is brought using the further drive assembly (28) into a range defined as favorable for the exhaust gas treatment.

Claims

1. A method for operating a drive device (10), comprising an internal combustion engine (12) and at least one further drive assembly (28) which is not an internal combustion engine (12), wherein an exhaust gas from the internal combustion engine (12) is treated by an exhaust gas treatment system (16), the method comprising:

determining the internal combustion engine (12) is not in an operating point defined as favorable for the exhaust gas treatment; and

bringing the operating point of the internal combustion engine (12) into the range defined as favorable for the exhaust gas treatment using the further drive assembly (28);

wherein the operating point is defined as favorable for the exhaust gas treatment is determined using a temperature of the exhaust gas and a ratio of NO2 to NOx in the exhaust gas.

2. The method according to claim 1, characterized in that the range of the operating points of the internal combustion engine (12) defined as favorable for exhaust gas treatment are defined by at least one map (49) and corresponding limit values, the map (49) formed by an effective mean pressure (80) and a rotation speed (78).

3. The method according to claim 1, characterized in that the operating point defined as favorable for the exhaust gas treatment is determined using at least one of the following input values:

volume flow of exhaust gas;

concentration of hydrocarbons in the exhaust gas;

concentration of nitrous oxides in the exhaust gas upstream of the exhaust gas treatment system (16);

concentration of nitrous oxides in the exhaust gas downstream of the exhaust gas treatment system (16);

enthalpy of the exhaust gas;

operating state of the exhaust gas treatment system (16);

driver'"'"'s desired torque;

gear engaged; and

charge state of an energy accumulator (34).

4. The method according to claim 3, characterized in that the further drive assembly is an electric motor (28) which is supplied with energy via an additional accumulator, and that using at least one of the input values, a value (63) characterizing the driver'"'"'s desired torque and a value (120) characterizing a load ratio of the internal combustion engine (12) and electric motor (28) are determined, and that the values determined (63, 120) are transmitted to a control device (44) for the internal combustion engine (12) and for the electric motor (28).

5. The method according to claim 3, characterized in that the further drive assembly is supplied with energy via an additional accumulator, and that using at least one of the input values, a value (63) characterizing the driver'"'"'s desired torque is determined, and that the value determined (63) is transmitted to a control device (44) for the internal combustion engine (12) and for the electric motor (28).

6. The method according to claim 2, characterized in that a lower and an upper limit value (105, 107) are predefined to limit the driver'"'"'s desired torque.

7. The method according to claim 3, characterized in that the further drive assembly is supplied with energy via an additional accumulator, and that using at least one of the input values, a value (120) characterizing a load ratio of the internal combustion engine (12) and electric motor (28) is determined, and that the value determined (120) is transmitted to a control device (44) for the internal combustion engine (12) and for the electric motor (28).

8. The method according to claim 1, characterized in that the internal combustion engine (12) is a diesel engine and that the exhaust gas treatment system (16) comprises an SCR catalyst (26).

9. The method according to claim 1, characterized in that the further drive assembly is supplied with energy via an additional accumulator.

10. The method according to claim 9, wherein the accumulator is an electric, hydraulic or thermal accumulator.

11. The method according to claim 9, wherein the accumulator is a hydraulic motor.

12. The method according to claim 9, wherein the accumulator is an electric motor (28).

13. The method according to claim 1, characterized in that the internal combustion engine (12) is controlled and/or regulated such that a torque of the internal combustion engine (12) is between 20% and 50% of the maximum torque of the internal combustion engine (12).

14. The method according to claim 1, characterized in that the internal combustion engine (12) is controlled and/or regulated such that a rotation speed (78) of the internal combustion engine (12) is between around 20% and 80% of the maximum rotation speed of the internal combustion engine (12).

15. The method according to claim 1, characterized in that at a comparatively low torque and/or low rotation speed (78) of the internal combustion engine (12), the electric motor (28) is operated as a generator in order to load the internal combustion engine (12) additionally and thus bring it into the desired operating point range.

16. The method according to claim 1, characterized in that at a comparatively high torque and/or high rotation speed (78) of the internal combustion engine (12), the electric motor (28) is operated as a motor in order to relieve the load on the internal combustion engine (12) and thus bring it into the desired operating point range.

17. The method according to claim 1, characterized in that it is carried out using stored data and/or at least one map (49) and/or at least one mathematical operation.

18. The method according to claim 1, characterized in that the drive device (10) is in particular in a motor vehicle.

19. A control device (44) for a motor vehicle, characterized in that it is adapted to perform a method according to claim 1.

20. A computer program (46) for a control device (44) of a motor vehicle, characterized in that it is programmed to perform a method according to claim 1.