Method and system for removing sulfur from a lean NOx trap

Patent metadata

Field	Value
Publication number	US-10047652-B2
Application number	US-201615216188-A
Country	US
Kind code	B2
Filing date	Jul 21, 2016
Priority date	Jul 22, 2015
Publication date	Aug 14, 2018
Grant date	Aug 14, 2018

Abstract

A method of removing sulfur from a lean NOx trap of a mild hybrid vehicle while the vehicle is stationary is disclosed, the method comprising connecting an electrical system of the vehicle to a large capacity external battery, operating an integrated starter generator driven by an engine of the vehicle as a generator to load the engine thereby allowing the engine to be operated at a higher torque level and rich of stoichiometric and storing the electrical energy produced by the integrated starter generator in the large capacity battery during the time period required for the removal of sulfur from the lean NOx trap.

First claim

What is claimed is:

1. A hybrid electric vehicle apparatus comprising:
a transmission;
an engine with a torque demand;
a lean NOx trap for receiving a flow of exhaust gas from the engine;
an electrical machine driven by the engine when the vehicle is stationary;
a controller configured to select a neutral gear of the transmission, operate the electrical machine as a generator to load the engine when the vehicle is stationary, and control the torque demand to produce a stoichiometrically rich exhaust gas flow to the lean NOx trap to remove sulfur from the trap; and
an external electrical load for absorbing electrical energy produced by the electrical machine, wherein the external electrical load is configured to connect to an electrical system of the vehicle.

2. The vehicle of claim 1 , wherein the external electrical load is a battery having a capacity sufficient to absorb the electrical energy produced by sulfur removal.

3. The vehicle of claim 1 , wherein the controller is further configured to monitor the exhaust gas flow to determine when to end sulfur removal and when to alternate rich and non-rich flows.

4. A hybrid vehicle system for removing sulfur from a lean NOx trap, comprising:
a controller configured to receive data indicative of required deSOx from sensors monitoring exhaust gas, operate an electrical machine as a generator to load a vehicle engine when the vehicle is stationary, and control an engine torque demand to produce a stoichiometrically rich exhaust gas flow to the NOx trap; and
an electrical load for absorbing energy produced by the electrical machine.

5. The system of claim 4 , wherein the controller is further configured to monitor the exhaust gas flow to determine when to end deSOx and when to alternate rich and non-rich flows.

6. The system of claim 4 , wherein the controller is an external electronic controller for connecting to an electrical system of a vehicle.

7. A mild hybrid vehicle system comprising:
a controller configured to, in response to data indicative of required deSOx from exhaust gas monitoring sensors and loading a vehicle engine by an electrical machine as a generator, increase an engine torque demand to produce a stoichiometrically rich exhaust gas flow to a lean NOx trap to remove sulfur; and
an external battery configured to absorb electrical energy produced by the electrical machine.

8. The mild hybrid vehicle system of claim 7 , further comprising a vehicle electrical system controlled by the controller and connected to the external battery.

9. The mild hybrid vehicle system of claim 7 , further comprising an external controller configured to operate the electrical machine to load the vehicle engine while the vehicle is stationary.

10. The mild hybrid vehicle system of claim 7 , wherein the external battery has a capacity sufficient to absorb the electrical energy produced by the electrical machine during sulfur removal.

11. The mild hybrid vehicle system of claim 7 , wherein the controller is further configured to monitor the exhaust gas flow composition from sensors to determine when deSOx is required, when to end deSOx, and when to alternate rich and non-rich flows.

Assignees

• Ford Global Tech Llc

Inventors

• Naidu Paspuleti Ashish Kumar
• Wright James
• Brittle Peter George

Classifications

• B60W2530/12

  Catalyst or filter state · CPC title

• B60W10/08

  including control of electric propulsion units, e.g. motors or generators · CPC title

• B60W10/06

  including control of combustion engines · CPC title

• B60Y2300/472

  Catalyst reactivation · CPC title

• B60W20/16

  for reducing engine exhaust emissions · CPC title