Method for exhaust-gas aftertreatment with reduced emissions

Patent metadata

Field	Value
Publication number	US-9038376-B2
Application number	US-201213565402-A
Country	US
Kind code	B2
Filing date	Aug 2, 2012
Priority date	Aug 26, 2011
Publication date	May 26, 2015
Grant date	May 26, 2015

Abstract

An exhaust-gas recirculation device for an internal combustion engine, a method for controlling an exhaust-gas recirculation device, a drive for a motor vehicle having an exhaust-gas recirculation device, and a motor vehicle having a drive of said type are described. The exhaust-gas recirculation device comprises a turbine, and an exhaust-gas aftertreatment device. The exhaust-gas aftertreatment device has an inlet connected to an outlet of the turbine, and is configured to reduce a pollutant content in the exhaust-gas flow. An electric grid heater is arranged between the outlet of the turbine and the inlet of the exhaust-gas aftertreatment device and is configured to heat the exhaust-gas flow.

First claim

The invention claimed is:

1. An exhaust-gas recirculation device for an internal combustion engine, the exhaust-gas recirculation device comprising:
a turbine, wherein a turbine inlet is connected to an exhaust manifold and wherein the turbine is configured to convert kinetic energy contained in an exhaust-gas flow through the exhaust manifold into rotational energy;
an exhaust-gas aftertreatment device, wherein an exhaust-gas aftertreatment device inlet is connected to an outlet of the turbine, the exhaust-gas aftertreatment device configured to reduce a pollutant content in the exhaust-gas flow, the exhaust-gas aftertreatment device comprising an electric grid heater arranged between the outlet of the turbine and the exhaust-gas aftertreatment device inlet and configured to heat the exhaust-gas flow;
a medium pressure exhaust-gas recirculation loop, wherein the medium pressure exhaust-gas recirculation loop has an inlet connected to an outlet of the electric grid heater, and is arranged upstream of the exhaust-gas aftertreatment device; and
a temperature sensor, wherein the temperature sensor is arranged downstream of the electric grid heater and upstream of the exhaust-gas aftertreatment device and measures a temperature of the exhaust-gas flow.

2. The exhaust-gas recirculation device of claim 1 , wherein the electric grid heater outputs a heating power of less than 1100 watts, preferably less than 1000 watts, and wherein the turbine has a fixed geometry.

3. The exhaust-gas recirculation device of claim 2 , further comprising:
a high pressure exhaust-gas recirculation loop including an inlet upstream of the turbine, an outlet upstream of a compressor, a high pressure valve, an EGR cooler, and an EGR cooler valve, wherein the high pressure exhaust-gas recirculation loop is in fluid communication with the medium pressure exhaust-gas recirculation loop.

4. A drive for a motor vehicle, the drive comprising an exhaust-gas recirculation device and an internal combustion engine connected to the exhaust-gas recirculation device, the exhaust-gas recirculation device comprising:
a turbine, wherein the turbine has an inlet connected to an exhaust manifold and wherein the turbine is designed to convert kinetic energy contained in an exhaust-gas flow through the exhaust manifold into rotational energy;
an exhaust-gas aftertreatment device having an inlet connected to an outlet of the turbine, the exhaust-gas aftertreatment device configured to reduce a pollutant content in the exhaust-gas flow, the exhaust-gas aftertreatment device further comprising an electric grid heater arranged between the outlet of the turbine and the inlet of the exhaust-gas aftertreatment device and configured to heat the exhaust-gas flow;
a medium pressure EGR loop including an inlet downstream of the electric grid heater and upstream of the exhaust-gas aftertreatment device, an outlet upstream of a compressor, and a medium pressure EGR valve;
a high pressure EGR loop including an inlet upstream of the turbine, an outlet upstream of the compressor, a high pressure EGR valve, an EGR cooler, and an EGR cooler valve;
a bypass line fluidically coupling the high pressure EGR loop with the medium pressure EGR loop, having an inlet downstream of the high pressure EGR valve and upstream of the EGR cooler and EGR cooler valve, and an outlet downstream of the medium pressure EGR valve and upstream of the compressor; and
a temperature sensor arranged downstream of the electric grid heater and upstream of the exhaust-gas aftertreatment device and which measures a temperature of the exhaust-gas flow.

5. The drive of claim 4 , having a control unit, the control unit comprising executable instructions to:
detect a start of the internal combustion engine;
check a state of an electrical supply source, and wait a duration of a waiting time period, wherein the duration of the waiting time period is ended in accordance with the state of the electrical supply source;
output heating power of less than 1100 watts, preferably less than 1000 watts, from the electric grid heater to the exhaust-gas flow of the internal combustion engine during a first time period, the first time period following the waiting time period; and
end the output of heating power to the exhaust-gas flow.

6. A method for engine emissions reduction, comprising:
during a first condition, powering a grid heater using an energy storage device to raise an exhaust-gas temperature;
during a second condition, injecting fuel to raise the exhaust-gas temperature; and
during a third condition, maintaining the exhaust-gas temperature by outputting power to the grid heater, injecting fuel, recycling the exhaust-gas, and cooling recycled exhaust-gas with an exhaust-gas recycle cooler coupled upstream of a charge-air cooler, wherein recycling the exhaust-gas comprises diverting a portion of the exhaust-gas to one or more exhaust-gas recycle lines, wherein the one or more exhaust-gas recycle lines comprise a high-pressure exhaust-gas recycle stream directed through the exhaust-gas recycle cooler and a high-pressure exhaust-gas recycle valve upstream from the grid heater, and a mid-pressure exhaust-gas recycle stream and a mid-pressure exhaust-gas recycle valve downstream from the grid heater.

7. The method of claim 6 , wherein:
the first condition comprises the exhaust-gas temperature being less than a first threshold temperature;
the second condition comprises the exhaust-gas temperature being greater than the first threshold temperature;
the third condition comprises the exhaust-gas temperature being greater than a second threshold temperature, the second threshold temperature being greater than the first threshold temperature; and
wherein the exhaust-gas temperature comprises an exhaust-gas temperature upstream from the exhaust-gas aftertreatment device and downstream from the grid heater.

8. The method of claim 7 , wherein the first condition further comprises a state-of-charge of an electrical energy storage device being greater than a threshold state-of-charge, and wherein the second condition further comprises the state-of-charge of the electrical energy storage device being less than the threshold state-of-charge.

9. The method of claim 8 , wherein the first condition further comprises after a threshold time has elapsed following detection of an engine start and the exhaust-gas temperature is below the second threshold exhaust-gas temperature.

10. The method of claim 7 , further comprising, during the third condition, cooling an engine intake airflow with an intake air cooler.

11. The method of claim 8 , wherein the energy storage device is coupled to a generator and wherein the generator converts kinetic energy to electrical energy for storage at the energy storage device.

12. The method of claim 6 , wherein:
the first condition comprises a pressure drop across a diesel particulate filter (DPF) being greater than a threshold pressure drop and a state-of-charge of an energy storage device being greater than a threshold state-of-charge;
the second condition comprises the pressure drop across the diesel particulate filter being greater than the threshold pressure drop and the state-of-charge of the energy storage device being less than the threshold state-of-charge; and
the third condition comprises the exhaust-gas temperature being greater than a DPF regeneration temperature.

13. The method of claim 12 , wherein the first condition further comprises after a threshold time has elapsed following detection of an engine start.

Assignees

• Petrovic Simon
• Vigild Christian Winge
• Ford Global Tech Llc

Inventors

• Petrovic Simon
• Vigild Christian Winge

Classifications

• F02M25/0718 Primary

  Mechanical Engineering · mapped topic

• F02D21/08

  the other gas being the exhaust gas of engine · CPC title

• F02M25/0709

  Mechanical Engineering · mapped topic

• Y02T10/121

  Cross-Sectional Technologies · mapped topic

• F02M25/0707

  Mechanical Engineering · mapped topic